Robustness in half-metallicity, thermophysical and structural properties of Co2YAl (Y = Pd, Ag) Heuslers: a first-principles perspective

Abstract

Heusler materials validates an extensive range of properties characteristically for the prospective high-tech interests. The extensive tunability of these materials through chemical substitutions as well as structural designs sorts the family explicitly fascinating. Self-consistent density functional theory, based on the full-potential linearized augmented plane wave is employed within the WIEN2k simulation code to investigate the structural, magneto-electronic and thermophysical properties of Co2PdAl and Co2AgAl Heusler compounds. The steadiness in P–V plot designates the absence of any structural phase transition from a cubic symmetry structure towards other structural phase. The GGA allows calculating the exchange-correlation energy. The proposed compounds are found stable in a Cu2MnAl prototype phase state. The cohesive and formation energy calculations approve the thermodynamic stability of compounds. The optimized lattice parameters in the stable Fm-3m phase are 5.90 Å for Co2PdAl and 5.97 Å for Co2AgAl respectively. At Fermi level, these alloys exhibit 100% spin polarization and display half-metallicity. The charge shearing among the constituents’ atoms is presented through the two-dimensional (2D) electron density plot with unique color contrast. The low anharmonicity possessed by the material is favored by the thermal parameters and compounds is predicted stable at a wider range of pressure and temperatures.