First-principles study on the Y-site Rh doping effects of the inverse Heusler alloy Ti₂RuSn

The first-principles calculations within the DFT are performed to investigate effects of the more-d electrons doping on the Y-site of inverse Heusler compound Ti₂RuSn. The results show that with the increase of the doping concentration, the magnetism of inverse Heusler alloy Ti₂RuSn increases linearly from 2 μ_B to 3μ_B. Besides, the half-metallic property is not damaged and the band gap gradually widens. When the doping concentration is 75%, the width of the band gap is extended from 0.45 eV to 0.54 eV, and the Fermi level is adjusted to get closer to the middle of the band gap, indicating that the compound Ti₂Ru_0.75 Rh_0.75 Sn has a relatively stable half-metallicity compared to the ideal bulk. In order to analyze the stability of the doping systems, we calculated their relative formation energies. The results showed that their formation energies are all negative, and the higher the doping concentration is, the lower the formation energy is. That is to say, the inverse Heusler alloy Ti₂RuSn is susceptible to the influence of the doped element Rh, and its electronic structure and band structure can be effectively regulated by the high-concentration Rh doping, so as to obtain the Heusler compounds with more stable half-metallicity, better performance and higher practicability. (authors)