Magnetic and structural transitions in the melt-spun Heusler alloy Ni53Mn25Al22

We report on the magnetic properties and structural transitions of the melt-spun ribbon Ni53Mn25Al22 alloy by means of resistance, differential scanning calorimetry (DSC) and magnetization measurements. The Ni53Mn25Al22 ribbon having a B2 structure exhibits a magnetic transition from antiferromagnetic to paramagnetic state, and a structural transition of austenitic–martensitic character with a Ms of 278 K. The calculated effective paramagnetic moment of 4.47 μB per formula unit reveals that the Mn atoms contribute to the paramagnetism of the B2 phase in this alloy.