First-Principles Investigation on the Fully Compensated Ferrimagnetic Behavior in Ti_2NbSb and TiZrNbSb

The electronic structures of Ti_2NbSb with Hg_2CuTi structure and TiZrNbSb with LiMgPdSn structure are investigated using first-principles calculations. The results indicate that Ti_2NbSb is a fully compensated ferrimagnetic spin-gapless semiconductor with an energy gap of 0.13 eV, and TiZrNbSb is a half-metallic fully compensated ferrimagnet with a half-metallic gap of 0.17 eV. For Ti_2NbSb, the total energy of the Hg_2CuTi structure is 0.62 eV/f.u. higher than that of the L2_1 structure, which is the ground state, and for TiZrNbSb, the total energy of the structure considered in this work is only 0.15 eV/f.u. larger than that of the ground state. Thus both of them may be good candidates for spintronic applications.