Martensitic and intermartensitic transitions in Ni₅₀Mn₂₀Cu₅Ga₂₁Al₄ Heusler alloy

Intermartensitic and martensitic transitions on polycrystalline Ni50Mn20Cu5Ga21Al4 Heusler alloys were studied through magnetization, heat capacity and electrical resistivity measurements. The occurrence of an intermartensitic transition depends on whether the sample undergoes heat treatment, while the martensitic transition is independent of the annealing process. After an annealing treatment, martensitic and intermartensitic transitions are observed at 264 K and 181 K respectively, both showing large thermal hysteresis. Both transitions affects the magnetic response of the zero field cooled and field cooled magnetic measurements. Similar effects are also observed on the electrical resistivity and specific heat of the alloys. (C) 2013 Elsevier B.V. All rights reserved