Systematic materials design for phase-change memory with small density changes for high-endurance non-volatile memory applications

The optical properties of transition-metal-based ternary tellurides have been systematically examined by density functional theory simulations. Based on an empirical law, which correlates density change with the optical contrast between the amorphous and crystalline phases of chalcogenides, the density changes occurring upon crystallization for hypothetical materials have been predicted. Cr₂Ge₂Te₆ was found theoretically to be one of the best materials for phase-change memory applications owing to its small density change. This novel criterion will be useful in the screening of materials yet to be experimentally realized, and will help target promising materials for high-endurance phase-change memory applications.