Fluid Oxygen Becomes Metallic

Fluid oxygen becomes metallic at a pressure of 1.2 Mbar and temperatures around 4500 K, discovered Marina Bastea (925-424-2803, bastea1@llnl.gov), Arthur C. Mitchell, and William J. Nellis of the Lawrence Livermore National Laboratory (LLNL). Although other groups have reported metallic oxygen formed by compressing the solid phase, this is the first time anyone has managed to make a metal from the disordered liquid phase.

To create the metallic fluid, the researchers fired a projectile at a reservoir of liquid oxygen trapped between two single-crystal sapphire anvils. The resulting shockwaves produced the metal-forming conditions for periods of 100-200 ns. The experimental technique is similar to the one used by Weir et. al. at LLNL for groundbreaking experiments leading to the first creation of metallic hydrogen in 1996 (Update 263). The experiment should stimulate theoretical progress in the relatively immature field of physics involving warm fluids at high densities and pressures. (Physical Review Letters, 2 April 2001; text at Physics News Select.)