Neutron Diffraction Study of Heusler Type Alloy Mn_0.47V_0.28Al_0.25

Abstract

Crystal and magnetic structures of an annealed Mn–V–Al ternary alloy were investigated by powder neutron diffraction. Neutron diffraction measurements confirmed clearly that the Mn–V–Al alloy specimen with approximate composition Mn₂VAl annealed at 1023 K for 48 h has the Heusler (L2₁)-type structure. Our studies on the annealed alloy specimen, Mn_1.88V_1.12Al_1.00, showed that Mn atom occupies preferentially the simple cubic Mn sublattice α(A+C), while V and Alatoms occupy the B and D sublattices, respectively, in the bcc structure composed of four equivalent fcc sublattices A, B, C and D. It was suggested strongly that Mn atom has the magnetic moment (1.5±0.3)μ_B, in the sublattice α and couples antiferromagnetically with V atom which has the magnetic moment 0.9μ_B in the B sublattice.