Effects of pressure on the structure and properties of layered ferromagnetic Cr2Ge2Te6

Abstract

Cr2Ge2Te6 is a rare layered ferromagnetic semiconductor that represents a promising material for novel thermoelectric and spintronic devices. High pressure is an effective way to change the electronic structure, and profoundly affects the physical and chemical properties of two-dimensional (2D) layered materials. Here we combined experimental results and theoretical calculations to investigate the structural evolution and properties of Cr2Ge2Te6under high pressure. It is found that Cr2Ge2Te6 undergoes an isostructural phase transition from layered to non-layered structure at ~14 GPa, accompanied with a semiconductor to metal transition, which is distinct from the previous reports. The pressure-induced metallization is verified by the overlap of the valence and conduction bands, and the layered-to-non-layered isostructural transition is attributed to the enhanced interlayer Te–Te interaction by First-principles calculations. Our results provide a potential pathway to control the structure and property of layered materials and possibility for conceptually new devices via pressure engineering.