Electronic structure of Ga[sub 1 - x]Cr[sub x]N and Si-doping effects studied by photoemission and x-ray absorption spectroscopy
G. S. Song, M. Kobayashi, J. I. Hwang, T. Kataoka, M. Takizawa et al.
The electronic structure of the magnetic semiconductor GaCrN, and the effect of Si doping on it have been investigated by photoemission and soft x-ray absorption spectroscopy. We have confirmed that Cr in GaN is predominantly trivalent when substituting for Ga and that Cr 3d states appear within the ... [Phys. Rev. B 78, 033304 (2008)] published Thu Jul 17, 2008.
Doubly degenerate orbital system in honeycomb lattice: Implication of orbital state in layered iron oxide
J. Nasu, A. Nagano, M. Naka, and S. Ishihara
We study a doubly degenerate orbital model on a honeycomb lattice. This is a model for orbital states in multiferroic layered iron oxides. The classical and quantum models are analyzed by spin-wave approximation, Monte Carlo simulation, and Lanczos method. A macroscopic number of degeneracy exists i ... [Phys. Rev. B 78, 024416 (2008)] published Thu Jul 17, 2008.
Modeling the Berezinskii-Kosterlitz-Thouless transition in NiGa[sub 2]S[sub 4]
Chyh-Hong Chern
In the two-dimensional superfluidity, the proliferation of the vortices and the antivortices results in a class of phase transition, the Berezinskii-Kosterlitz-Thouless (BKT) transition. This class of phase transition is also anticipated in the two-dimensional magnetic systems. However, its existenc ... [Phys. Rev. B 78, 020403 (2008)] published Thu Jul 17, 2008.
Quantum mechanics of superconducting nanowires
S. Khlebnikov
In a short superconducting nanowire connected to bulk superconducting leads, quantum phase slips behave as a system of linearly (as opposed to logarithmically) interacting charges. This system maps onto quantum mechanics of a particle in a periodic potential. We show that, while the state with a hig ... [Phys. Rev. B 78, 014512 (2008)] published Thu Jul 17, 2008.
Effects of frustration on the anisotropic triangular lattice bosons
Jing-Yu Gan
We study the extended hard-core Bose-Hubbard model with nearest-neighbor interactions on a triangular lattice with spatial anisotropy by quantum Monte Carlo simulations. The effects of the geometric frustration or the anisotropic strength, represented by the ratio t/t between the intrachain nearest- ... [Phys. Rev. B 78, 014513 (2008)] published Thu Jul 17, 2008.
Antiferromagnetic ordering of energy levels for a spin ladder with four-spin cyclic exchange: Generalization of the Lieb-Mattis theorem
Tigran Hakobyan
The Lieb-Mattis theorem is generalized to an antiferromagnetic spin-ladder model with four-spin cyclic exchange interaction. We prove that for J>2 K, the antiferromagnetic ordering of energy levels takes place separately in two sectors, which remain symmetric and antisymmetric under the reflection ... [Phys. Rev. B 78, 012407 (2008)] published Thu Jul 17, 2008.
Observation of room temperature ferromagnetism in Ga:ZnO: A transition metal free transparent ferromagnetic conductor
V. Bhosle and J. Narayan
This paper reports our results on room temperature ferromagnetism characteristics in Ga-doped ZnO. The Ga-doped ZnO films were grown epitaxially on (0001) sapphire with Ga concentration up to 5 at. %. Detailed x-ray diffraction and high resolution transmission electron microscopy results showed a ... [Appl. Phys. Lett. 93, 021912 (2008)] published Thu Jul 17, 2008.
Room-temperature ferromagnetism of Zn[sub 0.97]Co[sub 0.03]O pressed nanocrystalline powders
Jifan Hu, Hongwei Qin, Tianfeng Xue, Ensi Cao, and Dengtao Li
ZnCoO nanocrystalline powders were prepared by sol-gel method with a low annealing temperature of 450 degrees C. The as-synthesized ZnCoO powders were paramagnetic. However, after compaction under a pressure of 94 MPa, the ZnCoO pressed powders show a weak room-temperature ferromagnetism embedded ... [Appl. Phys. Lett. 93, 022510 (2008)] published Thu Jul 17, 2008.
Enhanced magnetoelectric coefficient (alpha) in the modified BiFeO[sub 3]--PbTiO[sub 3] system with large La substitution
Anupinder Singh, Arti Gupta, and Ratnamala Chatterjee
Magnetoelectric coupling coefficient (alpha) values of 0.88 mV/cm/Oe at 200 Oe and magnetocapacitive effects are reported in solid-solution BFLFPT with large La substitution (50:50 in BF). Enhancement of magnetic, dielectric, and ferroelectric properties is also observed. The solid solution shows ... [Appl. Phys. Lett. 93, 022902 (2008)] published Thu Jul 17, 2008.
Scattering of backward spin waves in a one-dimensional magnonic crystal
A. V. Chumak, A. A. Serga, B. Hillebrands, and M. P. Kostylev
Scattering of backward volume magnetostatic spin waves from a one-dimensional magnonic crystal, realized by a grating of shallow grooves etched into the surface of an yttrium iron garnet film, was experimentally studied. Rejection frequency bands were clearly observed. The rejection efficiency and t ... [Appl. Phys. Lett. 93, 022508 (2008)] published Thu Jul 17, 2008.
Room temperature electrical spin injection in remanence
S. Hovel, N. C. Gerhardt, M. R. Hofmann, F.-Y. Lo, A. Ludwig et al.
We demonstrate electrical spin injection from ferromagnetic Fe/Tb multilayer structures with remanent perpendicular magnetization into GaAs-based light-emitting diodes at room temperature. Using a reverse-biased Schottky contact and a MgO tunnel contact, respectively, we achieve spin injection at re ... [Appl. Phys. Lett. 93, 021117 (2008)] published Thu Jul 17, 2008.
Energy Minimization and ac Demagnetization in a Nanomagnet Array
X. Ke, J. Li, C. Nisoli, Paul E. Lammert, W. McConville et al.
We study ac demagnetization in frustrated arrays of single-domain ferromagnetic islands, exhaustively resolving every (Ising-like) magnetic degree of freedom in the systems. Although the net moment of the arrays is brought near zero by a protocol with sufficiently small step size, the final magnetos ... [Phys. Rev. Lett. 101, 037205 (2008)] published Thu Jul 17, 2008.
Kakuyanagi, Kumagai, and Matsuda Reply:
K. Kakuyanagi, K. Kumagai, and Y. Matsuda
A Reply to the Comment by V. F. Mitrovic et al.. ... [Phys. Rev. Lett. 101, 039702 (2008)] published Thu Jul 17, 2008.
Comment on ``Texture in the Superconducting Order Parameter of CeCoIn[sub 5] Revealed by Nuclear Magnetic Resonance''
V. F. Mitrovic, G. Koutroulakis, M. Klanjsek, M. Horvatic, C. Berthier et al.
A Comment on the Letter by K. Kakuyanagi et al., Phys. Rev. Lett. 94, 047602 (2005). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 101, 039701 (2008)] published Thu Jul 17, 2008.
Reversal mechanisms in perpendicularly magnetized nanostructures
Justin M. Shaw, Stephen E. Russek, Thomas Thomson, Michael J. Donahue, Bruce D. Terris et al.
We demonstrate that magnetic reversal in perpendicularly magnetized nanostructures is highly dependent on the nature and condition of the edges. To understand the impact of edge damage, we compare nanostructures created by ion milling to those prepared on prepatterned substrates. The size- and tempe ... [Phys. Rev. B 78, 024414 (2008)] published Wed Jul 16, 2008.
Erratum: Enhanced triplet superconductivity in noncentrosymmetric systems [Phys. Rev. B [bold 75], 172511 (2007)]
Takehito Yokoyama, Seiichiro Onari, and Yukio Tanaka
... [Phys. Rev. B 78, 029902 (2008)] published Wed Jul 16, 2008.
Electron gas at the interface between two antiferromagnetic insulating manganites
M. J. Calderon, J. Salafranca, and L. Brey
We study theoretically the magnetic and electric properties of the interface between two antiferromagnetic and insulating manganites: LaCaMnO, a strong correlated insulator, and CaMnO, a band insulator. We find that a ferromagnetic and metallic electron gas is formed at the interface between the two ... [Phys. Rev. B 78, 024415 (2008)] published Wed Jul 16, 2008.
Evidence of local superconductivity in granular Bi nanowires fabricated by electrodeposition
Mingliang Tian, Nitesh Kumar, Moses H. W. Chan, and Thomas E. Mallouk
An unusual enhancement of resistance (i.e., a superresistivity) below a certain characteristic temperature T was observed in granular Bi nanowires. This superresistive state was found to be dependent on the applied magnetic field as well as the excitation current. The suppression of T by magnetic fi ... [Phys. Rev. B 78, 045417 (2008)] published Wed Jul 16, 2008.
Frustration-induced quantum phase transitions in a quasi-one-dimensional ferrimagnet: Hard-core boson map and the Tonks-Girardeau limit
R. R. Montenegro-Filho and M. D. Coutinho-Filho
We provide evidence of a superfluid-insulator transition (SIT) of magnons in a quasi-one-dimensional quantum ferrimagnet with isotropic competing antiferromagnetic spin interactions. This SIT occurs between two distinct ferrimagnetic phases due to the frustration-induced closing of the gap to a magn ... [Phys. Rev. B 78, 014418 (2008)] published Wed Jul 16, 2008.
Magnon-mediated thermal conductivity in the dimerized spin-gap compound BaCu[sub 2]V[sub 2]O[sub 8]
C. S. Lue, C. N. Kuo, D. S. Tasi, Y. K. Kuo, Zhangzhen He et al.
We have measured the thermal conductivity (kappa) of the quasi-one-dimensional spin-gap compound BaCuVO with heat flow parallel and perpendicular to the chain axis. Distinctive differences in the magnitude and temperature dependence between these directions have been observed. A weak but non-negligi ... [Phys. Rev. B 78, 012406 (2008)] published Wed Jul 16, 2008.
Large-scale Monte Carlo simulations of the three-dimensional XY spin glass
J. H. Pixley and A. P. Young
We study the XY spin glass by large-scale Monte Carlo simulations for sizes up to 24, down to temperatures below the transition temperature found in earlier work. The data for the larger sizes show more marginal behavior than that for the smaller sizes, indicating that the lower critical dimension i ... [Phys. Rev. B 78, 014419 (2008)] published Wed Jul 16, 2008.
Rattling motion of [sup 140]Ce(<--[sup 140]La) confined in the hexaboride cage
W. Sato, A. Shinohara, and Y. Ohkubo
Rattling motion of the probe Ce(<--La) confined in the B cage of LaB was observed by means of the time-differential perturbed angular correlation technique. The time scale of the motion is in the order of 10-10 s at room temperature. The activation energy of the slow motion at higher temperatures ( ... [Phys. Rev. B 78, 012301 (2008)] published Wed Jul 16, 2008.
Switchable magnetic dipole induced guided vortex motion
N. Verellen, A. V. Silhanek, W. Gillijns, V. V. Moshchalkov, V. Metlushko et al.
We present evidence of magnetically controlled vortex motion in an Al film on top of a periodic array of Permalloy square rings. The resulting magnetic template generates a strongly anisotropic pinning potential landscape for vortices in the superconducting layer. Transport measurements show that th ... [Appl. Phys. Lett. 93, 022507 (2008)] published Wed Jul 16, 2008.
Measurement of the critical curve of a synthetic antiferromagnet
Cosmin Radu, Dorin Cimpoesu, Alexandru Stancu, and Leonard Spinu
In this paper, we propose a method for a synthetic antiferromagnet structure's critical curve determination. The method is based on reversible susceptibility's singularities detection, as the magnetic field is swept along easy axis, in both positive and negative direction, while a hard axis bias fie ... [Appl. Phys. Lett. 93, 022506 (2008)] published Wed Jul 16, 2008.
Anisotropic Effect of Cd and Hg Doping on the Pauli Limited Superconductor CeCoIn[sub 5]
Y. Tokiwa, R. Movshovich, F. Ronning, E. D. Bauer, P. Papin et al.
We studied the effect of impurity on the first order superconducting (SC) transition and the high field-low temperature (HFLT) SC state of CeCoIn by measuring the specific heat of CeCo(InCd) with x=0.0011, 0.0022, and 0.0033 and CeCo(InHg) with x=0.000 16, 0.000 32, and 0.000 48 at temperatures down ... [Phys. Rev. Lett. 101, 037001 (2008)] published Wed Jul 16, 2008.
Dy[sub 2]Ti[sub 2]O[sub 7] Spin Ice: A Test Case for Emergent Clusters in a Frustrated Magnet
Taras Yavors'kii, Tom Fennell, Michel J. P. Gingras, and Steven T. Bramwell
DyTiO is a geometrically frustrated magnetic material with a strongly correlated spin ice regime that extends from 1 K down to as low as 60 mK. The diffuse elastic neutron scattering intensities in the spin ice regime can be remarkably well described by a phenomenological model of weakly interacting ... [Phys. Rev. Lett. 101, 037204 (2008)] published Wed Jul 16, 2008.
Effect of hydrogen molecules on the electronic transport through atomic-sized metallic junctions in the superconducting state
P. Makk, Sz. Csonka, and A. Halbritter
In this paper the interaction of hydrogen molecules with atomic-sized superconducting nanojunctions is studied. It is demonstrated by conductance histogram measurements that the superconductors niobium, tantalum, and aluminum show a strong interaction with hydrogen, whereas for lead a slight interac ... [Phys. Rev. B 78, 045414 (2008)] published Tue Jul 15, 2008.
Exchange bias in nanoscale antidot arrays
D. Tripathy, A. O. Adeyeye, and N. Singh
Exchange bias effects have been systematically investigated in nanoscale Cu (10 nm)/NiFe (30 nm)/IrMn (30 nm)/Cu (2 nm) multilayer antidot arrays. The antidot arrays exhibit asymmetric and shifted hysteresis loops along the induced exchange bias direction, with higher coercivity and exchange bias ... [Appl. Phys. Lett. 93, 022502 (2008)] published Tue Jul 15, 2008.
Magnetic shape memory effect in thin foils
Oleg Heczko, Aleksandr Soroka, and Simo-Pekka Hannula
The magnetic shape memory (MSM) effect was observed in NiMnGa freestanding thin foils down to 90 [mu]m in thickness using top-down approach. The foils were prepared by thinning the bulk crystals exhibiting MSM effect. The effect was evaluated from the magnetization curves. The significant decrease ... [Appl. Phys. Lett. 93, 022503 (2008)] published Tue Jul 15, 2008.
Field effect in manganite ultrathin films: Magnetotransport and localization mechanisms
I. Pallecchi, L. Pellegrino, E. Bellingeri, A. S. Siri, D. Marre et al.
In this paper, we report on field-effect experiments in LaSrMnO side-gate channels patterned on ultrathin epitaxial films having thickness ranging from 12 to 4 unit cells. Transport mechanisms and competition between phases, under the effect of electric and magnetic fields, as well as of other pertu ... [Phys. Rev. B 78, 024411 (2008)] published Tue Jul 15, 2008.
Nonlinear electrodynamics in layered superconductors
V. A. Yampol'skii, Sergey Savel'ev, A. L. Rakhmanov, and Franco Nori
We analyze theoretically the effect of a weak nonlinearity on the propagation of Josephson plasma waves in layered superconductors. The nonlinearity originates from the Josephson relation between the current density across superconducting layers and gauge-invariant phase difference of the order para ... [Phys. Rev. B 78, 024511 (2008)] published Tue Jul 15, 2008.
Electric and magnetic modulation of fully strained dead layers in La[sub 0.67]Sr[sub 0.33]MnO[sub 3] films
Y. H. Sun, Y. G. Zhao, H. F. Tian, C. M. Xiong, B. T. Xie et al.
We report the electrical transport and magnetic properties of the dead layer of LaSrMnO grown on LaAlO substrate under the influence of magnetic field and electric voltage. The electrical resistance of the dead layer shows exponential decrease with both magnetic field and electric voltage, leading t ... [Phys. Rev. B 78, 024412 (2008)] published Tue Jul 15, 2008.
Intermolecular and intramolecular contributions to proton relaxation in p-methoxy-d[sub 3]-benzylidene-d[sub 1]-p-n-butyl-d[sub 9]-aniline
Ronald Y. Dong, E. Bock, John S. Lewis, and E. Tomchuk
A study of the temperature and frequency (4100 MHz) dependence of the proton spinlattice relaxation time in the nematic phase of p-methoxy-d-benzylidene-d-p-n-butyl-d-aniline (MBBA-d) is reported. The intra- and intermolecular contributions to the proton spinlattice relaxation rate are separated und ... [J. Chem. Phys. 72, 5014 (2008)] published Tue Jul 15, 2008.
M[o-umlaut]ssbauer studies of trimethyl and triphenyl tin chloride adsorbed on grafoil
S. Bukshpan and G. J. Kemerink
Trimethyl tin chloride [(CH)SnCl] and triphenyl tin chloride [(CH)SnCl] adsorbed on grafoil were studied by the Mossbauer resonance in Sn. The temperature dependence of the Mossbauer fraction and the anisotropy ratio of the quadrupole transitions in (CH)SnCl measured at two different angles supplied ... [J. Chem. Phys. 72, 4767 (2008)] published Tue Jul 15, 2008.
Electron spin resonance studies of magnetic soliton defects in polyacetylene
B. R. Weinberger, E. Ehrenfreund, A. Pron, A. J. Heeger, and A. G. MacDiarmid
We present electron spin resonance studies of the magnetic defect in undoped polyacetylene. Temperature dependences of the absorption spectra of (CD) and (CH) over the range 2295 K have been obtained. The properties of the magnetic defect in fully isomerized trans samples and in cis-rich samples are ... [J. Chem. Phys. 72, 4749 (2008)] published Tue Jul 15, 2008.
Relaxation in an A[sub 2] coupled spin system dissolved in a perdeuterated liquid crystal: The intermolecular dipolar random field cross relaxation term
J. Courtieu, J. Jullien, Nguyen Thoi Lai, A. Guillois, P. Gonord et al.
A perdeuterated nematic liquid crystal N- (p-ethoxybenzylidene) -p-n-butylaniline (EBBA-d, 98% deuterium) was synthesized to study relaxation of small molecules dissolved in anisotropic solvents. Proton spinlattice relaxation in the coupled A spin system of methylene chloride (CHCl) was studied usin ... [J. Chem. Phys. 72, 953 (2008)] published Tue Jul 15, 2008.
Proton spin T[sub 1] relaxation dispersion in liquid H[sub 2]O by slow proton-exchange
V. Graf, F. Noack, and G. J. Bene
We have measured the longitudinal proton spin relaxation time T in pure water as a function of temperature (10, 37, 80 degrees C) and Larmor frequency (50 Hz<=nu<=50 kHz) by means of field-cycling techniques. T becomes frequency dependent below nu[approximate]5 kHz due to the slow proton-exchange be ... [J. Chem. Phys. 72, 861 (2008)] published Tue Jul 15, 2008.
The chemical shift tensor for a strongly hydrogen-bonded proton: The carboxylic proton in KHCH[sub 2](COO)[sub 2]
Bo Berglund, Douglas G. Carson, and Robert W. Vaughan
The chemical shift tensor for the carboxylic proton in potassium hydrogen malonate has been determined from a proton multiple pulse experiment carried out at 270 MHz. Both the values of the averaged chemical shift relative to tetramethylsilane (TMS), ?=20.5 (5) and the chemical anisotropy, Deltasigm ... [J. Chem. Phys. 72, 824 (2008)] published Tue Jul 15, 2008.
Iodine chemical shifts in alkali metal metaperiodates and iodates
S. L. Segel and H. M. Vyas
Iodine chemical shift tensors have been measured using nuclear magnetic resonance in a variety of alkali metaperiodates, which include ammonium, potassium, silver, and sodium. The values for the isotropic component of the shift tensor range form +0.54% for silver to 0.54% for sodium. In saturated so ... [J. Chem. Phys. 72, 1406 (2008)] published Tue Jul 15, 2008.
Energy localization in substitutionally disordered solids. II. Studies by optical and optically detected magnetic resonance spectroscopy
D. D. Smith, D. P. Millar, and A. H. Zewail
In continuation of previous work, we present experimental measurements on the localization of triplet Frenkel excitons in isotopically doped phenazine and 1,4-dibromonaphthalene (2-D and 1-D effective excitation transfer topology, respectively). Dependence of steady state impurity aggregate (monomer ... [J. Chem. Phys. 72, 1187 (2008)] published Tue Jul 15, 2008.
EPR and ligand-ENDOR measurements of Cu (ii) in l-alanine single crystals
R. Calvo, S. B. Oseroff, and H. C. Abache
EPR experiments have been performed in l-alanine single crystals doped with copper in order to measure the gyromagnetic tensor of Cu(ii) and the hyperfine coupling tensor with Cu. The hyperfine coupling and the nuclear quadrupole interaction tensors of a ligand nitrogen have been obtained by ENDOR a ... [J. Chem. Phys. 72, 760 (2008)] published Tue Jul 15, 2008.
The magnetic properties of several quasi two-dimensional Heisenberg layer compounds: A new class of ferromagnetic insulators involving halocuprates
William E. Estes, D. Bruce Losee, and William E. Hatfield
Magnetic susceptibility measurements on powdered samples of bis(benzylammonium) tetrachlorocuprate (II), bis(phenethylammonium) tetrachlorocuprate(II), bis(3-phenyl-1-propylammonium) tetrachlorocuprate(II), and bis(benzylammonium) tetrabromocuprate(II) have shown that these four substances order fer ... [J. Chem. Phys. 72, 630 (2008)] published Tue Jul 15, 2008.
ESR studies of radical pairs of galvinoxyl radical in corresponding phenol matrix
Kazuo Mukai and Akemi Sogabe
ESR studies have been carried out on powder samples of galvinoxyl radical doped in its diamagnetic corresponding phenol matrix, which has the same crystal structure with that of galvinoxyl. The existence of a radical pair of the galvinoxyl has been confirmed by the observation of the ESR zero-field ... [J. Chem. Phys. 72, 598 (2008)] published Tue Jul 15, 2008.
The electronic structure of MnO[sub 4][sup 2 - ] as determined by ESR in K[sub 2]SO[sub 4]
M. Greenblatt and J. H. Pifer
The electron spin resonance of MnO has been studied at 4.2 K in single crystal KSO. The principal values of the g and A tensors are g=1.9757, g=1.9696, g=1.9445, A=21.0 x 10 cm, A=25.5 x 10 cm, and A=147.6 x 10 cm. A and g make an angle of 7.8 degrees and the only element of symmetry in the MnO tet ... [J. Chem. Phys. 72, 529 (2008)] published Tue Jul 15, 2008.
An experimental study of resolution of proton chemical shifts in solids: Combined multiple pulse NMR and magic-angle spinning
L. M. Ryan, R. E. Taylor, A. J. Paff, and B. C. Gerstein
High-resolution nuclear magnetic resonance spectra of protons in rigid, randomly oriented solids have been measured using combined homonuclear dipolar decoupling (via multiple pulse techniques) and attenuation of chemical shift anisotropies (via magic-angle sample spinning). Under those conditions, ... [J. Chem. Phys. 72, 508 (2008)] published Tue Jul 15, 2008.
Divalent europium in tetragonal sites of RbCl single crystals
J. Rubio O., W. K. Cory, and J. Hernandez A.
A new EPR spectrum of EU ions in RbCL single crystals is reported. The spin-Hamiltonian parameters describing the new site of EU ion in RbCL are obtained. (AIP) ... [J. Chem. Phys. 72, 2210 (2008)] published Tue Jul 15, 2008.
Electron paramagnetic resonance of Cr[sup 3 + ] in (NH[sub 4])[sub x]Tl[sub 1 - x]Al(SO[sub 4])[sub 2] [center-dot] 12H[sub 2]O
Vimal Kumar Jain
The electron paramagnetic resonance EPR of Cr has been studied in ammonium aluminium alum and thallium aluminium alum. The zero-field splitting has been studied with variations of composition. (AIP). ... [J. Chem. Phys. 72, 2208 (2008)] published Tue Jul 15, 2008.
M[o-umlaut]ssbauer effect investigation of the dynamics of ferrocene in liquid and glassy o-terphenyl
Adalberto Vasquez and Paul A. Flinn
Measurements of the Mossbauer spectra for Fe in ferrocene dissolved in o-terphenyl have been used to investigate the dynamics of the system, both in the glass and in the liquid. A rapid drop in the resonant fraction is observed above the glass transition temperature; the behavior is similar to that ... [J. Chem. Phys. 72, 1958 (2008)] published Tue Jul 15, 2008.
Nuclear magnetic relaxation and low temperature molecular mobility in organic glasses
W. Muller-Warmuth and W. Otte
Proton spinlattice relaxation times T at 15 and 30 MHz, and relaxation times in the rotating frame T, have been measured over the temperature range 20230 K for cyclohexane, cyclohexene, 1,3-cyclohexadiene, benzene, and substituted benzenes in glasses made of simple organic molecules. Results for dif ... [J. Chem. Phys. 72, 1749 (2008)] published Tue Jul 15, 2008.
Nuclear magnetic resonance shifts of paramagnetic organometallic actinide complexes. XII. [sup 1]H-NMR studies of neptunium (IV)-tetracyclopentadienide
B. Kanellakopulos, R. Klenze, G. Schilling, and A. H. Stollenwerk
... [J. Chem. Phys. 72, 6311 (2008)] published Tue Jul 15, 2008.
M[o-umlaut]ssbauer effect of [sup 129]I in n--sigma and pi--sigma charge-transfer complexes of iodine in the frozen solution
H. Sakai, Y. Maeda, S. Ichiba, and H. Negita
The Mossbauer effect of I was applied to investigate charge-transfer complexes of the nsigma and pisigma types in the carbon disulfide frozen solution at 16 K. In the case of nsigma type complexes such as triethylamineiodine and pyridineiodine, two chemical species of iodine, which correspond to the ... [J. Chem. Phys. 72, 6192 (2008)] published Tue Jul 15, 2008.
Nuclear magnetic relaxation study of solid sulfolan
D. W. Kydon, A. R. Sharp, M. E. Hale, and A. Watton
Sulfolan has been studied by pulsed NMR measurements of laboratory frame spinlattice relaxation T and rotating frame spinlattice relaxation times T in the temperature range from 186 to 339 K. The previously reported phase transition at 288 K has been observed, but the data also show the presence of ... [J. Chem. Phys. 72, 6153 (2008)] published Tue Jul 15, 2008.
Manganese hexacyanomanganate: Magnetic interactions via cyanide in a mixed valence Prussian blue type compound
R. Klenze, B. Kanellakopulos, G. Trageser, and H. H. Eysel
A Prussian blue type compound of the stoichiometric composition Mn(CN)xHO (x=0.57) is formed as the final product of hydrolysis of Na[Mn(CN)] in perchloric acid. IR and visible spectra as well as structural and magnetic data show that it is a mixed valence compound consisting of sixfold N-coordinate ... [J. Chem. Phys. 72, 5819 (2008)] published Tue Jul 15, 2008.
The temperature dependence of the diamagnetism of liquids
R. K. Kunze, Jr. and E. P. Day
We have measured the temperature dependence of the mass magnetic susceptibility of a representative group of liquids using a superconducting susceptometer. This study was undertaken to test the hypothesis that the known temperature dependence of the mass susceptibility of water [(13.350.03) x 10 K] ... [J. Chem. Phys. 72, 5809 (2008)] published Tue Jul 15, 2008.
Equation for the magnetic susceptibility of water
Edmund P. Day
The new precision magnetic susceptibility data of Philo and Fairbank make it possible for the first time to look for a parallel between water's response to a magnetic field and water's response to an electric field. These volume susceptibility (kappa) data measured at saturated vapor pressure over t ... [J. Chem. Phys. 72, 4434 (2008)] published Tue Jul 15, 2008.
Temperature dependence of the diamagnetism of water
J. S. Philo and W. M. Fairbank
We have measured the magnetic susceptibility of liquid water over the 20 to 60 degrees C range. By using a new instrument based on superconducting technology, we obtain a precision nearly two orders of magnitude higher than previous studies. Notably absent from these data is any evidence for the th ... [J. Chem. Phys. 72, 4429 (2008)] published Tue Jul 15, 2008.
ESR of vanadyl ions in Mg(H[sub 2]O)[sub 6]H[sub 2]EDTA single crystals
M. Narayana
An ESR study of single crystals of Mg(HO)HEDTA doped with very small concentrations of vanadyl ions showed the spectra and spin-Hamiltonian parameters to be totally different from those obtained in an earlier study with higher concentrations of VO. The results obtained in the present study are compa ... [J. Chem. Phys. 72, 4255 (2008)] published Tue Jul 15, 2008.
Superconductivity in graphite--potassium intercalation compounds
Mizuka Sano, Hiroo Inokuchi, Mototada Kobayashi, Shinji Kaneiwa, and Ikuji Tsujikawa
Superconductivity transitions were studied in golden graphitepotassium compounds. The transition temperature changes were studied by adding hydrogen to the compound. (AIP) ... [J. Chem. Phys. 72, 3840 (2008)] published Tue Jul 15, 2008.
[sup 31]P chemical shift and relaxation study of the pseudo-one-dimensional ferroelectric transition in CsD[sub 2]PO[sub 4]
R. Blinc, I. ZupanCiC, G. Lahajnar, J. Slak, V. Rutar et al.
The P chemical shift tensors sigma have been determined above and below T. The spinlattice relaxation time T (P) was measured as a function of temperature at 109.3 and 36.4 MHz. The paraelectric P chemical shift tensor was found to be the average of the two tensors observed in the ferroelectric phas ... [J. Chem. Phys. 72, 3626 (2008)] published Tue Jul 15, 2008.
Dynamics of cross relaxation in modulated systems: Application to nuclear magnetic double resonance of glassy polymers
T. T. P. Cheung and Robert Yaris
A statistical mechanical analysis, based on Mori's generalized Langevin equation, is presented for the dynamics of cross relaxation in modulated systems. Relaxation rate constants are given by Onsager's kinetic coefficients where the effects of lattice (heat bath) modulations are examined in terms o ... [J. Chem. Phys. 72, 3604 (2008)] published Tue Jul 15, 2008.
EPR powder spectrum of SrCl[sub 2] [center-dot] 6H[sub 2]O:Gd[sup 3 + ]
M. Rappaz
The EPR spectrum of powdered Srcl6HoGd is reported. The powder samples used in the experiments were obtained by total hydration of an hydrous Srcl:Gd powder sample at room temperature in a humid atmosphere.(AIP) ... [J. Chem. Phys. 72, 3432 (2008)] published Tue Jul 15, 2008.
A multiple pulse proton NMR study of alpha-oxalic acid dihydrate
Bo Berglund and Robert W. Vaughan
The chemical shift tenson for the water molecule in alpha-oxalic acid dihydrate was measured using a multiple pulse, NMR technique. The high resolution proton speclia were recorded at room temperature.(AIP) ... [J. Chem. Phys. 72, 3424 (2008)] published Tue Jul 15, 2008.
Conduction- and localized-electron spin resonance in the lithium--methylamine system: Inferences for the existence of the metallic compound tetramethylaminelithium(zero), Li(CH[sub 3]NH[sub 2])[sub 4]
Peter P. Edwards, Andrejs R. Lusis, and M. J. Sienko
Electron spin resonance (ESR) studies of fluid and frozen solutions of lithium in anhydrous methylamine are reported. The composition and temperature dependence of the ESR properties (electron spin relaxation times, electronic g factor) are indicative of metallic compound formation in the lithiummet ... [J. Chem. Phys. 72, 3103 (2008)] published Tue Jul 15, 2008.
Deuteron spin alignment: A probe for studying ultraslow motions in solids and solid polymers
H. W. Spiess
Deuteron spin alignment offers a new possibility to investigate extremely slow rotational motions in solids and solid polymers. A convenient theoretical description of the creation and detection of spin alignment by application of the JeenerBroekaert pulse sequence is given for both static and slowl ... [J. Chem. Phys. 72, 6755 (2008)] published Tue Jul 15, 2008.
Electron spin echo modulation study of the geometry of solvated electrons in ethanol glass: An example of a molecular dipole oriented solvation shell
M. Narayana and Larry Kevan
The analysis of the electron spin echo modulation patterns of solvated electrons in variously deuterated ethanol glasses shows that four ethanol molecules constitute the first solvation shell of the solvated electron with average distances of 2.2 A to the OH protons, 3.3 A to the CH protons, and 3.8 ... [J. Chem. Phys. 72, 2891 (2008)] published Tue Jul 15, 2008.
[sup 19]F chemical shifts in some tetrafluoroborates
R. E. J. Sears
The F chemical shifts are measured for cesium, silver and ammonium tetrafluoroborates in the solid state and under ambient temperature and pressure conditions. The correlations between the chemical shift and ionic radii and with cation electronegativity are discussed. (AIP) ... [J. Chem. Phys. 72, 2888 (2008)] published Tue Jul 15, 2008.
Self-diffusion in binary liquid solutions of n-paraffins and hexafluorobenzene
E. von Meerwall and R. D. Ferguson
Steady and pulsed gradient spin echo measurements of the self-diffusion of both components (H and F NMR) at 80 degrees C were performed in solutions of CF and each of six n-paraffins between n-octane and n-hexatriacontane across the full concentration ranges; activation energies were also measured. ... [J. Chem. Phys. 72, 2861 (2008)] published Tue Jul 15, 2008.
Theory for broadband detection of ion cyclotron resonance signals
Robert T. McIver, Jr., Edward B. Ledford, Jr., and Richard L. Hunter
A complete line shape theory is developed for the transient response of a new type of ion cyclotron resonance (ICR) detector circuit. The detector is basically a balanced capacitance bridge which is sensitive to the abundance of gaseous ions stored in a static magnetic ion trap. For the first time, ... [J. Chem. Phys. 72, 2535 (2008)] published Tue Jul 15, 2008.
Electron spin echo modulation studies of tetracyanoethylene anion solvation in methanol, acetone, and dimethylsulfoxide: Evidence for molecular dipole oriented solvation shells around large anions
Tsuneki Ichikawa and Larry Kevan
Electron spin echo modulation studies have been carried out for the tetracyanoethylene anion (TCNE) in CDOH, CHOD, (CD)CO, and (CD)SO at 4.2 K to deduce details of the anion solvation geometry in these solvents. The deuterium modulation patterns have been analyzed using ratio analysis and complete s ... [J. Chem. Phys. 72, 2295 (2008)] published Tue Jul 15, 2008.
Size effects on the magnetization reversal behavior of exchange bias modulated thin films
Christine Hamann, Ingolf Monch, Rainer Kaltofen, Rudolf Schafer, Thomas Gemming et al.
Thin films of NiFe/IrMn/Ta with spatially modulated unidirectional anisotropy have been prepared by local oxidation of the antiferromagnetic IrMn layer. Varying the lateral dimensions and orientation of the stripe structures with respect to the direction of exchange bias, the films exhibited differe ... [J. Appl. Phys. 104, 013926 (2008)] published Tue Jul 15, 2008.
Magnetic and magnetoresistance behaviors of particulate iron/vinyl ester resin nanocomposites
Zhanhu Guo, H. Thomas Hahn, Hongfei Lin, Amar B. Karki, and David P. Young
Magnetoresistance (MR) behavior of vinyl ester monomer stabilized iron nanoparticles and heat-treated vinyl ester resin nanocomposites reinforced with iron nanoparticles were investigated. Vinyl ester monomer serves as a coupling agent with one side covalently bound onto the nanoparticle surface by ... [J. Appl. Phys. 104, 014314 (2008)] published Tue Jul 15, 2008.
Metastable phase formation and magnetic properties of the Fe--Nb system studied by atomistic modeling and ion beam mixing
K. P. Tai, Y. Dai, and B. X. Liu
With the aid of ab initio calculations, an n-body FeNb embedded-atom potential is first constructed and then applied to study the crystal-to-amorphous phase transition through molecular dynamic simulations. The simulations determine that the glass-forming range of the FeNb system is 1883 at. % of N ... [J. Appl. Phys. 104, 014914 (2008)] published Tue Jul 15, 2008.
Magnetism in Disordered Graphene and Irradiated Graphite
Oleg V. Yazyev
The magnetic properties of disordered graphene and irradiated graphite are systematically studied using a combination of mean-field Hubbard model and first-principles calculations. By considering large-scale disordered models of graphene, I conclude that only single-atom defects can induce ferromagn ... [Phys. Rev. Lett. 101, 037203 (2008)] published Tue Jul 15, 2008.
NMR Evidence for the Persistence of a Spin Superlattice Beyond the 1/8 Magnetization Plateau in SrCu[sub 2](BO[sub 3])[sub 2]
M. Takigawa, S. Matsubara, M. Horvatic, C. Berthier, H. Kageyama et al.
We present B NMR studies of the 2D frustrated dimer spin system SrCu(BO) in the field range 2731 T covering the upper phase boundary of the 1/8 magnetization plateau, identified at 28.4 T. Our data provide a clear evidence that above 28.4 T the spin superlattice of the 1/8 plateau is modified but do ... [Phys. Rev. Lett. 101, 037202 (2008)] published Tue Jul 15, 2008.
Magnetostatic interactions between magnetic nanotubes
J. Escrig, S. Allende, D. Altbir, and M. Bahiana
The investigation of interactions between magnetic nanotubes is complex and often involves substantial simplifications. In this letter an analytical expression for the magnetostatic interaction, taking into account the geometry of the tubes, has been obtained. This expression allows for the definiti ... [Appl. Phys. Lett. 93, 023101 (2008)] published Mon Jul 14, 2008.
Strong linewidth variation for spin-torque nano-oscillators as a function of in-plane magnetic field angle
K. V. Thadani, G. Finocchio, Z.-P. Li, O. Ozatay, J. C. Sankey et al.
We measure the microwave signals produced by spin-torque-driven magnetization dynamics excited by direct currents in patterned magnetic multilayer devices at room temperature as a function of the angle of a magnetic field applied in the sample plane. We find strong variations in the frequency linewi ... [Phys. Rev. B 78, 024409 (2008)] published Mon Jul 14, 2008.
Unusual thickness dependence of the superconducting transition of alpha -MoGe thin films
H. Tashiro, J. M. Graybeal, D. B. Tanner, E. J. Nicol, J. P. Carbotte et al.
Thin films of alpha-MoGe show progressively reduced T's as the thickness is decreased below 30 nm and the sheet resistance exceeds 100 Omega/[square, open]. We have performed far-infrared transmission and reflection measurements for a set of alpha-MoGe films to characterize this weakened supercondu ... [Phys. Rev. B 78, 014509 (2008)] published Mon Jul 14, 2008.
Pairing symmetry of CeCoIn[sub 5] detected by in-plane torque measurements
H. Xiao, T. Hu, C. C. Almasan, T. A. Sayles, and M. B. Maple
In-plane torque measurements were performed on heavy fermion CeCoIn single crystals in the temperature T range 1.8 K<=T<=10 K and applied magnetic field H up to 14 T. The normal-state torque is given by tau[proportional]H(1+T/T) sin 4phi. The reversible part of the mixed-state torque, obtained aft ... [Phys. Rev. B 78, 014510 (2008)] published Mon Jul 14, 2008.
Phase-dependent electronic specific heat of mesoscopic Josephson junctions
Hassan Rabani, Fabio Taddei, Olivier Bourgeois, Rosario Fazio, and Francesco Giazotto
We study the influence of superconducting correlations on the electronic specific heat in a diffusive superconductor-normal metal-superconductor Josephson junction. We present a description of this system in the framework of the diffusive-limit Green's function theory, taking into account finite tem ... [Phys. Rev. B 78, 012503 (2008)] published Mon Jul 14, 2008.
Electron spin resonance and microwave magnetoresistance in Ge:Mn thin films
R. Morgunov, M. Farle, M. Passacantando, L. Ottaviano, and O. Kazakova
We report a study of resonant and nonresonant microwave absorption in germanium thin films (t=120 nm) implanted with manganese to a concentration of x=28 at. %. The germanium matrix contains MnGe precipitates, Mn-rich ferromagnetic nanoclusters, and diluted Mn ions. Electron spin resonances (ESR) ... [Phys. Rev. B 78, 045206 (2008)] published Mon Jul 14, 2008.
Magnetization ground states and phase diagrams for a nanosized Co hollow sphere: An onion-type magnetization state
Desheng Kong, Siming Wang, and Chinping Chen
The magnetization ground states (MGSs) for a nanosized Co hollow sphere, with the outer radius, R<50 nm, have been studied numerically by micromagnetic simulation using object oriented micromagnetic framework (OOMMF). In addition to the originally known single domain and vortex-curling states, a th ... [J. Appl. Phys. 104, 013923 (2008)] published Mon Jul 14, 2008.
Correlation between site preference of ternary Mn addition in LaAg and superconductivity
S. Kumar, S. N. Kaul, J. Rodriguez Fernandez, L. Fernandez Barquin, and P. F. Henry
Investigation of structure, surface morphology, composition, and the superconducting-normal phase diagram of LaAgMn superconducting alloys with nominal composition c=0.0, 0.025, 0.05, 0.1, 0.2, and 0.3, reveals the following. The alloys with c=0, 0.025, and 0.05 are essentially single phase alloys w ... [J. Appl. Phys. 104, 013920 (2008)] published Mon Jul 14, 2008.
Magnetic anisotropy and resonance frequency of patterned soft magnetic strips
X. Chen, Y. G. Ma, and C. K. Ong
FeTaN thin films of 100 nm with in-plane uniaxial anisotropy were fabricated by rf magnetron sputtering and patterned into strips with width varied from 30 to 500 [mu]m along both the easy and hard magnetization axes of the unpatterned films. The values of effective magnetic anisotropy of the pa ... [J. Appl. Phys. 104, 013921 (2008)] published Mon Jul 14, 2008.
Magnetization processes in single-layer and laminated CoFe films patterned into multiscale elements with write-head-like geometries
X. Kong, S. McVitie, J. N. Chapman, J. M. R. Weaver, D. O. O'Donnell et al.
Lorentz microscopy has been used to study the micromagnetic processes occurring during the reversal of multiscale single and multilayer CoFe elements. The elements, which have similar dimensions to write heads used in magnetic recording, typically have length scales varying from 10 [mu]m in the ele ... [J. Appl. Phys. 104, 013925 (2008)] published Mon Jul 14, 2008.
Ultrahigh current-carrying capability in clean MgB[sub 2] films
C. G. Zhuang, S. Meng, C. Y. Zhang, Q. R. Feng, Z. Z. Gan et al.
We have studied the current-carrying capability of high quality epitaxial MgB films synthesized using the hybrid physical-chemical vapor deposition technique by both transport measurement in nanobridge constrictions and magnetization measurement. An extremely high self-field critical current density ... [J. Appl. Phys. 104, 013924 (2008)] published Mon Jul 14, 2008.
A high-energy inelastic neutron scattering investigation of the Gd--Co exchange interactions in GdCo[sub 4]B: Comparison with density-functional calculations
Olivier Isnard, Michael D. Kuz'min, Manuel Richter, Michael Loewenhaupt, and Robert Bewley
Inelastic neutron scattering is used to quantify the GdCo exchange interaction in GdCoB. A significant reduction is observed in comparison with the GdCo compound. A mean value of 130 T is obtained for the exchange field on the two Gd sites in GdCoB. The experimental results are compared with densit ... [J. Appl. Phys. 104, 013922 (2008)] published Mon Jul 14, 2008.
Magnetic relaxation under fast internal rotation in liquids
H. Versmold
In previous work magnetic relaxation under internal rotation frequently has been discussed in terms of the rotational diffusion model even for systems with rather low internal barriers. Here the internal rotation is taken as an ''extended diffusion'' process. In the limit of fast internal rotation, ... [J. Chem. Phys. 73, 5310 (2008)] published Mon Jul 14, 2008.
Orientation of tensorial interactions determined from two-dimensional NMR powder spectra
M. Linder, A. Hohener, and R. R. Ernst
Methods are described for determining the mutual orientation of molecular interaction tensors based on two-dimensional NMR powder spectra. Necessary conditions are derived under which this determination can be made, procedures for the computation and analysis of 2D powder spectra are indicated and a ... [J. Chem. Phys. 73, 4959 (2008)] published Mon Jul 14, 2008.
NMR study of hydrogen diffusion and phase determination of the Mg[sub 2]NiH[sub x] system
S. D. Goren, C. Korn, M. H. Mintz, Z. Gavra, and Z. Hadari
We have measured the temperature dependence of the hydrogen spin lattice relaxation time in the hydride (beta, beta[prime], gamma, delta) and solid solution phases of the MgNiH system. These gave the temperature ranges of the various phases. The hydrogen diffusion activation energy for the beta, bet ... [J. Chem. Phys. 73, 4758 (2008)] published Mon Jul 14, 2008.
[sup 23]Na second-order quadrupolar shifts and heat capacity anomalies in Na beta-alumina
John L. Bjorkstam, Paolo Ferloni, and Marco Villa
In the temperature region 100140 K the second-order quadrupolar shifts of Na in beta-alumina undergo a gradual but unusual change. In the same temperature range, contributions to the heat capacity of atoms in the conducting plane exhibit a maximum. These facts are considered as evidence for a 2D ''m ... [J. Chem. Phys. 73, 2932 (2008)] published Mon Jul 14, 2008.
An ESR study of molecular reorientation in liquids
F. G. Herring and P. S. Phillips
Electron spin resonance (ESR) has been used to study the reorientational correlation times (tau) of a series of bis(dialkyldithiocarbamato) Cu(II) spin probes, in toluene, as a function of temperature. It has been found that the linear relationship tau=C(eta/T)+tau is obeyed over most of the tempera ... [J. Chem. Phys. 73, 2603 (2008)] published Mon Jul 14, 2008.
Slow molecular motion detected in the NMR spectra of rotating solids
D. Suwelack, W. P. Rothwell, and J. S. Waugh
We present an approach for detecting and analyzing slow molecular motions in solids based on changes in the zero order sideband of an inhomogeneously broadened spin system under magic angle spinning conditions. The effect is discussed theoretically from the standpoint of second order perturbation th ... [J. Chem. Phys. 73, 2559 (2008)] published Mon Jul 14, 2008.
Deuteron spin--lattice relaxation from hindered rotations in molecular crystals
J. C. Pratt, A. Watton, and H. E. Petch
The D nuclear spinlattice relaxation is calculated for the situation in which molecular groups containing n deuterons undergo thermally activated hindered reorientations enabling each of the spins to sample each of n available sites, all of which are assumed to have quadrupole couplings (eqQ/h) of e ... [J. Chem. Phys. 73, 2542 (2008)] published Mon Jul 14, 2008.
The longitudinal spin lattice relaxation time of the uranyl phenanthraquinone radical ion complex
D. A. Hutchinson, K. S. Chen, J. Russell, and J. K. S. Wan
The longitudinal spin lattice relaxation time T for the uranyl phenanthraquinone radical complex ion (UOPQ) is much less than that for the phenanthraquinone radical anion PQ. A qualitative understanding of the effect is achieved by recognizing that the U atom has an enormous spinorbit coupling. A ca ... [J. Chem. Phys. 73, 1862 (2008)] published Mon Jul 14, 2008.
ESR of matrix isolated bromine atoms produced in the H+Br[sub 2] reaction
S. V. Bhat and W. Weltner, Jr.
The products of the H(D)+X reaction, where X is Br, Cl, or F, have been trapped in solid argon at 4 degrees K and observed via ESR. With Br as reactant the observed spectra are attributed to Br atoms electronically quenched in an axial crystal field. The spectra obtained using the other halogens we ... [J. Chem. Phys. 73, 1498 (2008)] published Mon Jul 14, 2008.
Erratum: Dynamics of the n-decylammonium chains in the perovskite-type layer structure compound (C[sub 10]H[sub 21]NH[sub 3])[sub 2]CdCl[sub 4]) [J. Chem. Phys. [bold 7][bold 1], 2118 (1979)]
R. Kind, S. Plesko, H. Arend, R. Blinc, B. Zeks et al.
... [J. Chem. Phys. 73, 1482 (2008)] published Mon Jul 14, 2008.
Double quantum cross polarization. Heteronuclear excitation and detection of NMR double quantum transitions in solids
P. Brunner, M. Reinhold, and R. R. Ernst
The application of HartmannHahn cross polarization for the enhancement and for the detection of NMR double quantum coherence is investigated. The matching conditions and relaxation rates are discussed. It is found, in particular, that the double quantum cross relaxation rate is four times that of si ... [J. Chem. Phys. 73, 1086 (2008)] published Mon Jul 14, 2008.
Pulsed spin locking in pure nuclear quadrupole resonance
R. S. Cantor and J. S. Waugh
The technique of pulsed spin locking in NMR has recently been applied to a pure NQR system, with results very similar to those obtained in the NMR case. However, the theoretical methods used to explain the NMR results are not applicable to the pure NQR case. Using a model of the NQR system, a method ... [J. Chem. Phys. 73, 1054 (2008)] published Mon Jul 14, 2008.
Magnetization and NMR in pure and mixed crystal Fe[S[sub 2]CN(C[sub 2]H[sub 5])[sub 2]] [sub 2]Cl[sub x]Br[sub 1 - x]: 3D-Ising ferromagnetism and evidence for a strain induced ground state
Gary C. DeFotis and J. A. Cowen
The magnetization along easy and hard magnetic axes has been measured in three single crystal samples of Fe[SCN(CH)]Cl Br (x=1.000, 0.712, and 0.204), between 1.2 and 4.2 K and in applied fields up to 13 000 Oe. In the pure chloride an effective saturation moment of 3.280.16 [mu] per iron ion is obs ... [J. Chem. Phys. 73, 2120 (2008)] published Mon Jul 14, 2008.
Mossbauer spectroscopy of the mixed-spin and high-spin states of Chromatium ferricytochrome c[prime]
M. M. Maltempo, T. H. Moss, and K. Spartalian
Mossbauer spectra are reported for Chromatium ferricytochrome c[prime] in the pH range 1.010.5. Measurements were made in the 150 degrees 4.2 degrees K range in the absence of an external field, and at 4.2 degrees K in longitudinal and transverse applied fields. Samples at pH 1.0 and 10.5, 150 d ... [J. Chem. Phys. 73, 2100 (2008)] published Mon Jul 14, 2008.
Correlations between proton chemical shift tensors, deuterium quadrupole couplings, and bond distances for hydrogen bonds in solids
Bo Berglund and Robert W. Vaughan
Correlations between parameters characterizing the proton chemical shift tensors for OHO bonded protons in solids and OO hydrogen bond distances and deuterium quadrupole coupling constants (eqQ/h) are presented. The isotropic value of the chemical shift correlates very well with both R and eqQ/h, wh ... [J. Chem. Phys. 73, 2037 (2008)] published Mon Jul 14, 2008.
High resolution [sup 1]H solid state NMR studies of polyethyleneterephthalate
T. T. P. Cheung, B. C. Gerstein, L. M. Ryan, R. E. Taylor, and D. R. Dybowski
Molecular motions and spatial properties of the solid polymer polyethyleneterephthalate have been investigated using high resolution H solid state NMR techniques. The longitudinal spin relaxation time Trho of protons (H) in the rotating frame was measured for a spin locking field ranging from 5 to 2 ... [J. Chem. Phys. 73, 6059 (2008)] published Mon Jul 14, 2008.
Sideband intensities in NMR spectra of samples spinning at the magic angle
Judith Herzfeld and Alan E. Berger
General integral and series expressions are derived for the intensities of sidebands observed in the magic angle spectra of inhomogeneously broadened I=1/2 systems. The expressions are evaluated for a wide range of shift parameters and the results used to construct graphical and numerical methods fo ... [J. Chem. Phys. 73, 6021 (2008)] published Mon Jul 14, 2008.
Electron paramagnetic resonance of VO[sup 2 + ] in hydrated crystals
Vimal Kumar Jain and Putcha Venkateswarlu
The electron paramagnetic resonance of VO ion impurities in single crystals of MRb(SO)6H0 where M=Mg, Fe; MgSO7HO; NaKCHO4HO; and (NH)COHO has been studied at room temperature and at X-band frequency region. Multiple trapping sites for vanadyl are observed in all the crystals. The vanadyl ions enter ... [J. Chem. Phys. 73, 30 (2008)] published Mon Jul 14, 2008.
Spin--lattice relaxation of reorienting or tunneling deuterated methyl groups
J. Tang, A. Pines, and S. Emid
The spinlattice relaxation of deuterated methyl groups, which is exponential at high temperatures, becomes nonexponential at low temperatures as evidence of the coupling between the Zeeman and tunneling systems. The dominant relaxation is considered to be the quadrupole interaction. Experimental res ... [J. Chem. Phys. 73, 172 (2008)] published Mon Jul 14, 2008.
Nuclear spin--lattice relaxation and site symmetry in phase II of solid CH[sub 4]
P. Calvani and F. De Luca
On the basis of Nijman's theory of relaxation in solid CH, T measurements at low T are here recognized to be important for determining the exact symmetry of the orienting field in phase II. An experiment in the range 60100 MHz would check unambiguously the EJK model prediction of a D site symmetry. ... [J. Chem. Phys. 73, 167 (2008)] published Mon Jul 14, 2008.
The determination of deuterium atom coordinates and nuclear quadrupole interactions in lanthanum nicotinate dihydrate crystals by Nd[sup 3 + ]--deuterium double resonance
Clyde A. Hutchison, Jr. and Thomas E. Orlowski
We have obtained the ENDOR (electron nuclear double resonance) spectra of the four deuterons of the two DO molecules coordinated to Nd dilutely substituted for La in La(CHNCO) (DO) (dimeric lanthanum nicotinate dihydrate) molecules in single crystals. From the measurements of the values of the aniso ... [J. Chem. Phys. 73, 1 (2008)] published Mon Jul 14, 2008.
Excitations and magnetic ground state in Co(pyr)[sub 2]Cl[sub 2]
C. H. W. Swuste, A. C. Phaff, and W. J. M. de Jonge
The magnetic ground state and field induced magnetic arrays are derived by the method of Kudo and Katsura. From the critical fields a set of exchange parameters can be deduced. Spin cluster resonances are detected in the various phases as well as in the paramagnetic phase at T>~T, where evidence for ... [J. Chem. Phys. 73, 4646 (2008)] published Mon Jul 14, 2008.
The specific heat anomaly in triethylamine--heavy water near the critical solution point
E. Bloemen, J. Thoen, and W. Van Dael
The anomaly in the specific heat C has been investigated by means of a constant heating rate method. Accurate results could be obtained for ||T-T||/T values as small as 7 x 10. From a range shrinking procedure and nonlinear-least-squares fits to the data we obtained alpha=alpha[prime]=0.1070.002, wh ... [J. Chem. Phys. 73, 4628 (2008)] published Mon Jul 14, 2008.
The generation and ESR investigation of the BeF radical in rare gas matrices
L. B. Knight, Jr., M. B. Wise, A. G. Childers, E. R. Davidson, and W. R. Daasch
The 13 electron BeF radical has been generated and trapped in argon and krypton matrices at 12 K and studied via ESR spectroscopy. Comparisons are made between BeF and other similar radicals. The calculated dipole moment for BeF is 1.1 D. The magnetic parameters in argon are g=2.001, g=2.001, A(Be)= ... [J. Chem. Phys. 73, 4198 (2008)] published Mon Jul 14, 2008.
Proton spin--lattice relaxation in meta-carborane
Peter Beckmann and Armin Wendel
The proton spin lattice relaxation time, T has been measured at 30 MHz in meta-carborane between 171 and 303 degrees K. The temperature dependence of T in meta-carborane is discussed.(AIP) ... [J. Chem. Phys. 73, 3514 (2008)] published Mon Jul 14, 2008.
Broadening by strains of lines in the g-parallel region of Cu[sup 2 + ] EPR spectra
W. Froncisz and James S. Hyde
Linewidths of the m=3/2 and 1/2 hyperfine lines in the g-parallel region of several square-planar copper complexes with oxygen ligands in frozen solutions have been measured at 2.6, 3.8, and 8.9 GHz. A theory has been developed in terms of distributions of molecular bonding parameters that satisfact ... [J. Chem. Phys. 73, 3123 (2008)] published Mon Jul 14, 2008.
Proton NMR in a hydrogen molybdenum bronze
A. C. Cirillo, Jr., L. Ryan, B. C. Gerstein, and J. J. Fripiat
Solid state nuclear magnetic resonance (NMR) has been used to probe the nature of hydrogen in the hydrogen bronze HMoO. The line shape of the proton NMR at room temperature is found to be associated only with shielding anisotropy. Below 230 K, dipolar interactions become important in broadening the ... [J. Chem. Phys. 73, 3060 (2008)] published Mon Jul 14, 2008.
Exciton scattering and the dephasing of ESR and optical absorption lines: The 1,2,4,5-tetrachlorobenzene triplet exciton problem
R. D. Wieting and M. D. Fayer
The relationship between exciton scattering induced dephasing of the ESR and the optical transitions of triplet exciton bands is examined by properly including exchange in the line shape formalism. First, a simple heuristic model demonstrates that while the optical dephasing time can be associated w ... [J. Chem. Phys. 73, 744 (2008)] published Mon Jul 14, 2008.
Proton coordinates in Er(C[sub 2]H[sub 5]SO[sub 4])[sub 3] [center-dot] 9H[sub 2]O and ErCL[sub 3] [center-dot] 6H[sub 2]O from single crystal NMR studies
Setsuko Sato, Amikam Reuveni, and Bruce R. McGarvey
Proton coordinates have been determined for all hydrate protons in Er(CHSO)9HO and ErCl6HO from NMR studies on single crystals. The paramagnetic NMR shift in these systems has been determined to be completely point dipolar within experimental error. In the case of Er(CHSO)9HO it was found that ''jum ... [J. Chem. Phys. 73, 712 (2008)] published Mon Jul 14, 2008.
Protonic species in H[sub 1.7]MoO[sub 3]
R. E. Taylor, L. M. Ryan, P. Tindall, and B. C. Gerstein
The nature of hydrogen in HMoO has been investigated with solid state nuclear magnetic resonance. Samples prepared utilizing wet chemical reduction of MoO in zinc and HCl, and dry hydrogen spillover on platinized MoO have been characterized by proton NMR with and without strong proton decoupling and ... [J. Chem. Phys. 73, 5500 (2008)] published Mon Jul 14, 2008.
Cation quadrupole couplings in alkali metal nitrates: Rubidium, cesium, and potassium
S. L. Segel
Phase IV RbNO gives rise to three distinct Rb nuclear quadrupole couplings at 20 degrees C. This observation supports the proposed crystal structure, trigonal, with space group P3. For phase II CsNO, isomorphous with the rubidium salt, only an upper limit to the Cs nuclear quadrupole coupling can be ... [J. Chem. Phys. 73, 4146 (2008)] published Mon Jul 14, 2008.
Stable Mean-Field Solution of a Short-Range Interacting SO(3) Quantum Heisenberg Spin Glass
C. M. S. da Conceicao and E. C. Marino
We present a mean-field solution for a quantum, short-range interacting, disordered, SO(3) Heisenberg spin model, in which the Gaussian distribution of couplings is centered in an antiferromagnetic (AF) coupling [overline J]>0, and which, for weak disorder, can be treated as a perturbation of the pu ... [Phys. Rev. Lett. 101, 037201 (2008)] published Mon Jul 14, 2008.
Experimental Research on Pyromagnetic Effect of PVC Sheet
Yingshe Luo, Jianxin Su, Yongzhong Zhang, Xuhua Deng, Shengming Chen et al.
Experimental Research on PVC sheet with defects was conducted under tensile load. In the region of viscoplastic damage a deformation heat was given out and the temperature was increased and measured by instrument named HX8600. Using the surveying system exploited by authors, a heat-force coupling py ... [AIP Conf. Proc. 1027, 1417 (2008)] published Mon Jul 14, 2008.
Aging Phenomena in Thin Polymer Films Observed through Volume and Dielectric Susceptibility
Koji Fukao and Daisuke Tahara
Glassy dynamics was investigated for thin films of poly(2-chlorostyrene) (P2CS) through complex electric capacitance measurements using dielectric relaxation spectroscopy. During the isothermal aging process the real part of the electric capacitance increased with time, whereas the imaginary part de ... [AIP Conf. Proc. 1027, 1309 (2008)] published Mon Jul 14, 2008.
Polarization Study Of Lambda[sub c] Baryon Using Data From The Fermilab E831 Experiment
S. Carrillo, C. Castromonte, and C. Oropeza
Using the data obtained by the Fermilab E831 photoproduction Experiment, a spin polarization study of Lambda baryon is presented for two of its decay modes: Lambdapi and Kp. Preliminary polarization results for Lambdapi and values of the product alphaP for Kp are obtained. We show that, for Lambdapi ... [AIP Conf. Proc. 1026, 303 (2008)] published Mon Jul 14, 2008.
Muonium Spectrum Beyond the Nonrelativistic Limit
Axel Weber
A generalization of the Gell-MannLow theorem is applied to the antimuon-electron system. The bound state spectrum is extracted numerically. As a result, fine and hyperfine structure are reproduced correctly near the nonrelativistic limit (and for arbitrary masses). We compare the spectrum for the re ... [AIP Conf. Proc. 1026, 204 (2008)] published Mon Jul 14, 2008.
Origin of ferromagnetism of MnSi[sub 1.7] nanoparticles in Si: First-principles calculations
Shin Yabuuchi, Hiroyuki Kageshima, Yukinori Ono, Masao Nagase, Akira Fujiwara et al.
The origin of the magnetism of MnSi nanoparticles in Si is investigated using the first-principles calculations: bulk and interface effects are considered. The bulk magnetic property is expected to be affected by stoichiometry, strain, and charge accumulation. Stoichiometry and charge accumulation i ... [Phys. Rev. B 78, 045307 (2008)] published Fri Jul 11, 2008.
Comparative NMR investigation of the Re-based borides
C. S. Lue, Y. F. Tao, and T. H. Su
We report a systematic study of the rhenium-based borides, ReB, ReB, and ReB, by means of the B nuclear magnetic resonance (NMR) spectroscopy. While ReB and ReB are superconductors, ReB exhibits no superconducting signature but is of current interest due to its superhard mechanical property. Since t ... [Phys. Rev. B 78, 033107 (2008)] published Fri Jul 11, 2008.
Structure and properties of the kagome compound YBaCo[sub 3]AlO[sub 7]
M. Valldor, N. Hollmann, J. Hemberger, and J. A. Mydosh
Large single crystals of YBaCoAlO were synthesized in a floating-zone furnace. Powder and single-crystal x-ray data confirm that the structure belongs to the swedenborgite compound family (P6mc, a=6.28098(3) A, and c=10.21200(5) A). YBaCoAlO can reversibly absorb/desorb oxygen up to about O accord ... [Phys. Rev. B 78, 024408 (2008)] published Fri Jul 11, 2008.
Flux tubes and the type-I/type-II transition in a superconductor coupled to a superfluid
Mark G. Alford and Gerald Good
We analyze magnetic-flux tubes at zero temperature in a superconductor that is coupled to a superfluid via both density and gradient (entrainment) interactions. The example we have in mind is high-density nuclear matter, which is a proton superconductor and a neutron superfluid, but our treatment is ... [Phys. Rev. B 78, 024510 (2008)] published Fri Jul 11, 2008.
Universal dependence on disorder of two-dimensional randomly diluted and random-bond [plus-minus]J Ising models
Martin Hasenbusch, Francesco Parisen Toldin, Andrea Pelissetto, and Ettore Vicari
We consider the two-dimensional randomly site diluted Ising model and the random-bond J Ising model (also called the Edwards-Anderson model), and study their critical behavior at the paramagnetic-ferromagnetic transition. The critical behavior of thermodynamic quantities can be derived from a set of ... [Phys. Rev. E 78, 011110 (2008)] published Fri Jul 11, 2008.
Properties of Pt-supported Co nanomagnets from relativistic density functional theory calculations
Adriano Mosca Conte, Stefano Fabris, and Stefano Baroni
The electronic, structural, and magnetic properties of Co-based low-dimensional nanostructures supported by Pt surfaces are investigated using computer simulations based on density functional theory. The effects of the local orientation of the magnetization, including the magnetic anisotropy energy, ... [Phys. Rev. B 78, 014416 (2008)] published Fri Jul 11, 2008.
Numerical study of quantum vortex phase diagram in two-dimensional superconductors
Kiyokazu Myojin, Ryusuke Ikeda, and Shigeru Koikegami
Vortex phase diagrams of weakly disordered two-dimensional (2D) superconductors under a magnetic field perpendicular to the plane are numerically studied based on a recent development on the corresponding issue in three-dimensional (3D) systems with a low density of columnar defects at high temperat ... [Phys. Rev. B 78, 014508 (2008)] published Fri Jul 11, 2008.
Nodal Quasiparticles and the Onset of Spin-Density-Wave Order in Cuprate Superconductors
Andrea Pelissetto, Subir Sachdev, and Ettore Vicari
We present a theory for the onset of spin-density-wave order in the superconducting ground state of the cuprates. We compute the scaling dimensions of allowed perturbations of a relativistic fixed point with O(4)[direct-product]O(3) symmetry, including those associated with the fermionic nodal Bogol ... [Phys. Rev. Lett. 101, 027005 (2008)] published Fri Jul 11, 2008.
Phase and Vortex Correlations in Superconducting Josephson-Junction Arrays at Irrational Magnetic Frustration
Enzo Granato
Phase coherence and vortex order in a Josephson-junction array at irrational frustration are studied by extensive Monte Carlo simulations using the parallel-tempering method. A scaling analysis of the correlation length of phase variables in the full equilibrated system shows that the critical tempe ... [Phys. Rev. Lett. 101, 027004 (2008)] published Fri Jul 11, 2008.