Effect of pressure on the magnetic, mechanical, and dynamical properties of L10-FePt alloy

Abstract

The magnetic, elastic, and dynamical properties of L10-type FePt alloy are investigated under high pressure using first-principles calculations. The critical pressure of ferromagnetism collapse is identified as 96.7 GPa, and the alloy exhibits mechanical stability over the studied pressure range up to 120 GPa. Below the critical pressure, ductility hardly changes with pressure, and the elastic anisotropy is enhanced by pressure. The ductility and elastic anisotropy of the system show a sudden decrease beyond the critical pressure. Dynamical stabilities under ambient and high pressures are verified by phonon spectra. The alloy is dynamically stable before the critical pressure of 96.7 GPa due to spontaneous magnetization. Finally, the anisotropy of phonon density of states under high pressure is evaluated in detail, and the result indicates that the degree of anisotropy is almost independent of pressure.