Pressure-Induced Composite Phase Transition of Solid Oxygen

Abstract

Solid oxygen shows a rich variety of phase transitions under high pressures such as structural phase transition, magnetic transition, insulator-metal transition, superconducting transition (pressure-induced composite phase transition). In this article, the present status of a theoretical understanding about the insulator-metal transition, magnetic transition and structural phase transition of solid oxygen under high pressures is reviewed on the basis of the results of first-principles electronic structure calculations obtained by our group and other groups.