Neutron diffraction study of Ga and Al doped MnNiGe alloys

Magnetic equiatomic alloys (MEAs) of the general formula MM'X (M, M' = transition metals, X = Si, Ge, Sn) undergo martensitic transition on cooling from high temperature. Recently, these alloys are identified as new class of shape memory alloy and attracted considerable attention due to their rewarding magneto- functionality. Recent studies indicate that a controlled doping at the Ge site in a MnNiGe alloy by Al, Sn or Ga results in a ferromagnetic (FM) hexagonal to antiferromagnetic orthorhombic MPT. In this proposal, we would like to perform powder neutron diffraction on two suitable alloys belong to MEA family of nominal compositions MnNiGe0.928Ga0.072 and MnNiGe0.9Al0.1 at ambient pressure to unveil the nature of the magnetic ground state.