Effect of Co substitution on the magnetic and transport properties of the half-metallic ferrimagnet Mn2VGa

Mn 2 − x Co x V Ga  ( x = 0.5 , 0.75 and 1) compounds were synthesized by arc melting to investigate the effect of cobalt substitution on the magnetic and transport properties of the half-metallic ferrimagnetic compound Mn2VGa. The lattice parameter value decreases with the substitution of Co. The compounds Mn1.25Co0.75VGa and MnCoVGa showed a substantial reduction in magnetic moment due to anti-parallel alignment of the Mn moment with Co and V moments and the M z value for these compounds observed to be 0.35 μ B and 0.37 μ B respectively. The magnetic moment per formula unit at 5 K, estimated from magnetization data, indicates a slight deviation from the Slater–Pauling relation. The Curie temperature was found to decrease with the Co substitution. Low temperature resistivity data in the temperature range of 18–100 K was observed to follow the relation ρ = ρ 0 + A T 2 + B T 4.5