Electronic and thermo-mechanical behavior of Ni-based intermetallic compounds

This study employs density functional theory (DFT) to explore the structural, electronic, optical, elastic, and thermoelectric properties of Ni 2 X (X [Formula: see text] Al or Sb) intermetallic compounds. Both alloys crystallize in a stable cubic Fd-3m (227) structure, confirming metallic behavior through band structure and density of states (DOS) analyses dominated by Ni 3d states. Optical studies reveal strong ultraviolet absorption, peaking at 13.5[Formula: see text]eV for Ni 2 Al and 7.5[Formula: see text]eV for Ni 2 Sb, indicating promise for optoelectronic device applications. Elastic calculations indicate that Ni 2 Al is moderately ductile (G/[Formula: see text]), while Ni 2 Sb is stiff and brittle (G/[Formula: see text]) with exceptional shear resistance ([Formula: see text] [Formula: see text]GPa). Thermal and thermoelectric analyses show that both materials reach the Dulong–Petit limit at high temperatures, with Ni 2 Sb exhibiting a higher Debye temperature (562[Formula: see text]K) and improved thermoelectric performance (ZT [Formula: see text] 0.06 at 1400[Formula: see text]K). These findings suggest Ni 2 Al is suitable for lightweight, thermally responsive applications, whereas Ni 2 Sb is better suited for high-temperature, mechanically demanding, and energy-conversion environments.