Insights into crystal structure, elasticity, lattice dynamics, and thermodynamics of ternary magnesium alloy MgZn2Ce

Abstract

We performed first-principles investigations on ternary magnesium alloy MgZn2Ce at high pressure to explore the pressure effect on the crystal structure, elastic property, lattice dynamics, and thermodynamic characterization. The calculated high-pressure single-crystal elastic constants manifested that MgZn2Ce is mechanically stable up to 20 GPa. We found not that the phonon dispersion curves throughout the entire Brillouin region and phonon density of states of MgZn2Ce show any instability or anomaly, hence the dynamical stability is strong under compression up to 20 GPa. Concurrently, the Raman and infrared-active phonon modes at Г point of the Brillouin zone are classified by factor group theory. Combining the quasi-harmonic approximation and Debye model, we further predict the thermal-physical properties of MgZn2Ce. It is hoped that physical properties predicted by this study will inspire researchers to synthesize new-type multiple magnesium alloys.