Mechanical, thermodynamic properties and phase transition in crystal CaZn2 under high pressure — a DFT study

Abstract

In this work, a detailed study of the structural, mechanical and thermodynamic changes in CaZn2 under pressure range of 0–40 GPa is performed, and two different exchange correlations (XC) of GGA-PBE and LDA are used. It is found that the enthalpy values imply that CaZn2 undergoes a phase transition from CeCu2-type phase to Laves phase at 3.45 GPa with XC of GGA-PBE and 1.43 GPa with LDA, which is consistent with previous experiments and parts of theoretical conclusions. Furthermore, the elastic stability criterion is used to study the elastic constants of CaZn2 under different pressures, confirming the stability of the CaZn2 structure from 0 GPa to 40 GPa. Finally, the thermodynamic properties of CaZn2 under pressures are comprehensively studied in detail.