DFT Calculation of the Electronic Properties of Cubic Ti3Sb Crystals with Adsorbed and/or Partially Substituted Nitrogen

Intermetallic alloys based on A15-type compounds, including cubic Ti3Sb, attract increasing interest due to their tunable electronic properties and potential for surface-related functional applications. Here, the interaction of nitrogen with Ti3Sb is systematically investigated using spin-polarized density functional theory within the GGA-PBE approximation. Nitrogen adsorption was analyzed on the Ti3Sb (111), (100), and (110) surfaces by considering top, bridge, and hollow sites at different surface coverages. Low nitrogen coverage was found to minimize lateral adsorbate interactions, allowing reliable evaluation of single-atom adsorption energies. Among the studied configurations, nitrogen adsorption at the hollow site of the Ti3Sb (111) surface is energetically most favorable. In addition, partial substitution of Ti or Sb atoms by nitrogen in Ti3Sb supercells was examined to assess its effect on bulk electronic properties. Nitrogen incorporation leads to pronounced modifications of the electronic band structure, density of states, and local magnetic moments, with a strong dependence on crystallographic direction. The calculated results reveal distinct electronic anisotropies originating from direction-dependent band dispersion and associated effective carrier masses. These findings clarify the role of nitrogen in tailoring both surface and bulk electronic characteristics of Ti3Sb and provide a theoretical basis for the targeted design of A15-type intermetallic materials for sensing, catalytic, and energy-related applications.