Half‐metallicity, magnetism, mechanical, thermal, and phonon properties of FeCrTe and FeCrSe half‐Heusler alloys under pressure

Abstract

The half-metallicity of Heusler alloys is quite sensitive to high pressure and disorder. To understand this phenomenon better, we systematically studied the half-metallic nature, magnetism, phonon, and thermomechanical properties of FeCrTe and FeCrSe Heusler alloys under high pressure using ab initio calculations based on density functional theory. The ground-state lattice constants for FeCrTe and FeCrSe alloys are 5.93 and 5.57 Å, respectively, consistent with available theoretical results. Formation energy, cohesive energy, elastic constants, and phonon dispersion confirmed that both compounds are thermodynamically and mechanically stable. The FeCrTe and FeCrSe alloys showed a half-metallic character with a band gap of 0.68 and 0.58 eV at 0 GPa pressure, respectively, and magnetic moments of 2.01 μ B for both alloys, using generalized gradient approximation (GGA) approximation. FeCrTe alloy changes from metallic to half-metallic above 30 GPa pressure using GGA + U. The elastic properties were scrutinized, and it was found that, at 0 GPa pressure, FeCrTe is ductile, and FeCrSe is brittle. Under pressure, FeCrSe becomes brittle above 10 GPa pressure. Average sound velocity V m , Debye temperature Ɵ D , and heat capacity C V were predicted under pressure. These outcomes will improve the integration of Fe-based half-Heusler alloys in spintronic devices.

Ab initio Prediction of Mechanical, Electronic, Magnetic and Transport Properties of Bulk and Heterostructure of a Novel Fe-Cr based Full Heusler Chalcogenide

“…This is in accordance with previous studies reported in the literature. [59][60][61] . The results are found to be significantly different for both the phases.…”

Strain induced electronic structure, and magnetic and structural properties in quaternary Heusler alloys ZrRhTiZ (Z = Al, In)

“…Depending upon the stoichiometry, Heusler alloys are divided into three categories: (i) equiatomic half-Heusler (XYZ), [12][13][14][15][16][17][18][19][20][21][22] (ii) 2:1:1 full-Heusler (X 2 YZ) [23][24][25][26][27][28][29] and (iii) equiatomic quaternary Heusler (XX YZ), in which X, X , Y are transition-metal (TM) elements and Z is the main group sp elements. [30][31][32][33][34][35][36][37][38][39][40] The equiatomic quaternary Heusler (EQH) alloys can be obtained by replacing one TM element X to another TM element X in the full-Heusler alloy X 2 YZ.…”