High-Pressure Phases and Properties of the Mg3Sb2 Compound

Pressure always plays an important role in influencing the structure configuration and electronic properties of materials. Here, combining density function theory and structure prediction algorithm, we systematically studied the Mg 3 Sb 2 system from its phase transition to thermodynamic and electronic properties under high pressure. We find that two novel phases, namely Cm and C 2/ m , are stable under high pressure. Calculation results of phonon dispersions showed that both novel phases have no imaginary frequency, which indicates that the novel phases are thermodynamically stable. Due to the larger ionic radius of Sb compared to N, P, and As elements, the Mg 3 Sb 2 compound shows a different electronic property at high pressure. The electronic calculations show that the novel phases of Cm and C 2/ m of Mg 3 Sb 2 possess metallic behavior under high pressure. These results provide new insights for understanding the Mg 3 Sb 2 compound.