Exploring the multifaceted properties: structural, electronic, magnetic, mechanical, thermodynamic, transport, and optical characteristics of rhodium-based half-Heusler alloys

Density functional theory was employed to investigate the structural, electronic, elastic, thermodynamic, and thermoelectric characteristics of RhNbZ (Z = Si, Ge) half-Heusler materials. Furthermore, RhNbZ (Z = Si, Ge) alloys adhere to the semiconductor behaviour dictated by the Slater–Pauling rule. Elastic property calculations affirm the mechanical stability of the compounds. Next, we use density functional perturbation theory (DEPT) to predict the dynamical context of these ordered systems. Utilizing the Debye quasi-harmonic model, we explored the thermodynamic properties of these half-Heusler alloys. The thermoelectric properties of the materials were evaluated using the semi-classical Boltzmann theory, which was implemented in the BoltzTraP code. A remarkably high figure of merit values for RhNbZ (Z = Si, Ge) compounds suggests their potential for thermoelectric applications across a wide temperature range. Optical properties, including dielectric function, absorption coefficient, refractive index, reflectivity, and optical conductivity, were calculated and discussed. Notably, the materials exhibit exceptional absorption coefficients α(ω) in the ultraviolet and visible regions of the light spectrum, indicating their suitability for applications in photovoltaic and optical equipment manufacturing.