Transport and magnetic properties of Mn2VAl: Search for half-metallicity

Polycrystalline Mn2VAl samples with the ordered L21 structure were examined by X-ray diffraction, magnetisation and resistivity measurements. The magneto moment at 5 K is 1.94 μB/f.u. and the residual resistivity is 13×10−8 Ω m, with little temperature dependence below 60 K. The low magnetoresistance (<0.1% at 1 T at 77 K) measured on polycrystalline samples or pressed powders makes it difficult to attribute a half-metallic character to Mn2VAl, as had been proposed on the basis of band structure calculation.