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

• Published in: Molecular physics Vol. 120; no. 18
• Main Authors: Kumar, Ashwani, Singh, Saurabh, Sofi, Shakeel Ahmad, Chandel, Tarun, Thakur, Naveen
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 17.09.2022; Taylor & Francis Ltd
• Subjects: Anharmonicity; Density functional theory; Electron density; electronic structure; First principles; Free energy; Half-metallic ferromagnetism; Heat of formation; Lattice parameters; Magnetic properties; Mathematical analysis; Metallicity; Palladium; Phase transitions; Plane waves; Polarization (spin alignment); Shearing; Silver; spintronics; Thermodynamic properties; Thermophysical properties
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2022.2120839

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 Co 2 PdAl and Co 2 AgAl 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 Cu 2 MnAl 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  $ {\AA} $ Å for Co 2 PdAl and 5.97  $ {\AA} $ Å for Co 2 AgAl 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.