DFT Study of Structural, Electronic, Magnetic and Thermodynamic properties of XMnZ₂ (X = Au, Hg, and Tl, Z = S, Se) Delafossites

In this study, we present a comprehensive exploration of the Delafossite composites using density functional theory (DFT) and the semi-classical Boltzmann simulations within the Wien2k framework. Our investigation includes structural, electronic, magnetic and thermal properties in the tetragonal phase, providing a holistic understanding of these materials. Firstly, the structural-magnetic stability of XMnZ₂ (X = Au, Hg, and Tl, Z = S, Se) was verified through ground-state energy calculations obtained from structural optimizations. Our results indicate a stable ferromagnetic phase for the six compounds. Moving on to electronic properties, we utilize the Trans-Blaha modified Becke Johnson (TB-mBJ) functional potential to elucidate the electronic behavior (metallic, half metallic, semiconductor or insolating) of the considered compounds in both up and down spin directions. Furthermore, spin-polarized band structures unveil a net magnetism in the range of 2.67µ_B to 4.02µ_B, highlighting the potential for spintronics applications. Finally, we investigate the thermodynamic properties using the quasi-harmonic model, where heat capacities at constant pressure and volume, entropy, Debye temperature, and thermal expansion coefficient are analyzed and discussed under both pressure and temperature effects. Overall our study provides a comprehensive understanding of the multifaceted properties of Delafossites, paving the way for their potential applications in various fields.