Crystal structure, magnetic and electrical transport properties of titanium-doped half-Heusler alloys Ni1−xTixMnSb.

Ni 1 − x TixMnSb polycrystalline alloys in the range 0 ≤ x ≤ 0. 2 0 were synthesized employing the standard solid-phase synthesis method. The crystal, magnetic, as well as electrical properties of the alloys were investigated using neutron powder diffraction and magneto-resistance measurements. The results reveal that the substitution of Ti for Ni within the temperature range of 2.5–300 K does not induce alterations in the crystal and magnetic structures of NiMnSb. The ordered Ni magnetic moment approaches zero. The study of the electrical transport properties of the Ni 1 − x TixMnSb alloys, where 0 ≤ x ≤ 0. 2 0 , has demonstrated a half-metallic state at low temperatures and metallic conductivity for temperatures exceeding 160 K. A semiconductor state manifests at titanium concentrations of x = 0.2 and was observed at temperatures below 21 K. The obtained experimental results are elucidated through first-principles theoretical calculations. [ABSTRACT FROM AUTHOR]