Disorder Control in Crystalline GeSb₂Te₄ Using High Pressure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Electronic phase-change memory (PCM) relies on tunable resistivity between amorphous and crystalline states.
• Atomic disorder in crystalline PCMs can create intermediate resistive states by localizing electronic states.

Purpose of the Study:

• To investigate the effect of high pressure on inducing disorder in crystalline PCMs.
• To explore novel mechanisms for modulating PCM properties and achieving amorphization.

Main Methods:

• Large-scale ab initio molecular dynamics simulations were employed.
• Analysis focused on antisite migration and its impact on electronic structure and lattice stability.

Main Results:

• High pressure lowers the energy barrier for antisite migration in crystalline PCMs.
• Increased compositional disorder leads to localized electronic states near the conduction band.
• Pressure-induced disorder contributes to the amorphization of crystalline PCMs.

Conclusions:

• Pressure is a novel tool for tuning electronic properties of PCMs through disorder engineering.
• Disorder-induced electron localization and lattice distortion offer new pathways for PCM device optimization and amorphization control.