Martensitic transformation and magnetic properties in high-Mn content Mn50Ni50−xInx ferromagnetic shape memory alloys

A series of Mn50Ni50−xInx (x = 9.75, 10, 10.25, 10.5 10.75, and 11) ferromagnetic shape memory alloys with Mn content as high as 50 at.% were prepared. The martensitic transformation (MT), magnetocaloric effect, and magnetoresistance in Mn50Ni50−xInx alloys were investigated. With x increasing from 9.75 to 11, the MT temperature decreased from 270 to 110 K and the Curie temperature of austenite remains relatively constant. Large positive magnetic entropy change and negative magnetoresistance were observed around MT temperatures in these alloys. Large magnetic entropy change and magnetoresistance would be ascribed to the temperature and magnetic field-induced MT in Mn50Ni50−xInx alloys.

► A series of Mn50Ni50−xInx alloys with a high Mn content of 50 at.% were prepared.
► Martensitic transformation temperature decreased with x increasing from 9.75 to 11.
► Large ΔS and MR were observed around martensitic transformation.
► Large ΔS and MR ascribed to temperature and field-induced martensitic transformation.