Magnetostructural transitions and adiabatic temperature variation in polycrystal and single-crystal Ni2MnGa alloys
The magnetocaloric response of off-stoichiometric Ni2MnGa polycrystal and single-crystal samples with a Curie temperature coincident with the martensitic transition temperature was investigated. The direct measurement of temperature change (ΔTad) during an adiabatic transformation under a maximum field variation ΔH = 5.6×106 A/m (7 T) was performed. The polycrystalline sample shows a maximum ΔTad ≈ 1.5 K at a temperature close to the structural transition. The value of ΔTad and the 20 K span of the ΔTad peak encourage further studies of the effect of microstructure on the magnetocaloric response of Ni2MnGa.
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The following article appeared in Journal of Applied Physics 99 (2006): 08K905 and may be found at http://dx.doi.org/10.1063/1.2162335.