Electric polarization is described in 2-D manganese-based organic-inorganic hybrids

A wide range of application areas can benefit from the continual development and understanding of organic-inorganic hybrid materials. These hybrid systems can combine and tailor properties found in both organic and inorganic materials through the homogeneous integration of these components at the atomic scale. Particularly of interest are polar hybrids, due to an ability to control their electronic properties. Although these hybrids have been used in products for several decades, recent advances offer opportunities to enhance and create new products.

New research presented in APL Materials considers the formation of an out-of-plane polar axis in manganese-based organic-inorganic hybrid materials, which is rare among these hybrid systems and more conventional layered perovskites. While in-plane polar phases can be beneficial for solar cells, out-of-plane polar phases can find applications in generating ferroelectricity which can be more facilely manipulated. This is useful for devices like ferroelectric-gate field effect transistors, in which the polarization of the top electrode can change the resistance.

This study provides a detailed examination of the crystal structure of the 2-D manganese hybrid material using X-ray diffraction at different temperatures. The work enables a better understanding of the underlying mechanism of the polar properties. The authors found that the way to describe the observed behavior was with the polar axis out-of-plane with respect to the inorganic sheets of the hybrid. They argue that this polarization is induced by the angle between the phenyl groups of adjacent organic layers in the structure.

This work provides a new understanding to generate ferroelectric behavior in 2-D organic-inorganic hybrids, which widens the field of applications of these materials.

Source: “Out-of-plane polarization in a layered manganese chloride hybrid,” by Machteld E. Kamminga, Romel Hidayat, Jacob Baas, Graeme R. Blake, and Thomas T. M. Palstra, APL Materials (2018). The article can be accessed at https://doi.org/10.1063/1.5024857 .