Magnetostructural phase transition in off-stoichiometric Ni–Mn–In Heusler alloy ribbons with low In content

Abstract We report features of microstructure, martensitic transformation, magnetic properties and magnetocaloric effect in three off-stoichiometric Ni 45 Mn 44 In 11 , Ni 47 Mn 41 In 12 and Ni 48 Mn 39 In 13 (nominal-compositions) alloys ribbons. They were selected in the 7.8 e/a e/a the valence electron concentration per atom, one of the parameters that determines functional properties displayed by these alloys near room-temperature. Although the real composition is shifted from nominal one in each sample, its influence on all here studied properties at the temperature range of 50–400 K is analyzed. Especially, the role played by Ni content in the decrease of magnetization observed in two alloys with respect to the third one with the lowest e/a . Ni content effect on the antiferromagnetic interaction present in the martensitic phase of the alloys ribbons is also evidenced.