Abstract The magnetocaloric effect (MCE) on Ni2−xPtxMnGa (x = 0.2, 0.3 and 1.0) shape memory Heusler alloys around martensite phase transition temperature (TM) is investigated by varying chemical pressure (Pt concentration). The magnetic entropy change (ΔSM) decreases with increasing chemical pressure for various external applied magnetic fields up to 3 T, and the width of thermal hysteresis increases with the increases of Pt concentration. The effect of hydrostatic pressure on both TM and ΔSM for Ni1.8Pt0.2MnGa is also investigated. We observed that the application of hydrostatic pressure increases TM (3.5 K/GPa) and stabilizes the martensite phase. The maximum magnetic entropy change (ΔSmax) of 9.31 J Kg−1 K-1is observed for a field change of 9 T at ambient pressure for Ni1.8Pt0.2MnGa. Further, the application of external pressure leads to the decrease of ΔSmax to 5.52 J Kg−1 K−1 at 0.91 GPa.

中文翻译：

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化学和外部静水压力对 Pt 掺杂 Ni2MnGa 形状记忆 Heusler 合金磁和磁热性能的影响

摘要 通过改变化学压力（Pt 浓度）研究了在马氏体相变温度 (TM) 附近对 Ni2−xPtxMnGa (x = 0.2、0.3 和 1.0) 形状记忆 Heusler 合金的磁热效应 (MCE)。对于高达 3 T 的各种外加磁场，磁熵变（ΔSM）随着化学压力的增加而减小，热滞宽度随着 Pt 浓度的增加而增加。还研究了静水压力对 Ni1.8Pt0.2MnGa 的 TM 和 ΔSM 的影响。我们观察到静水压力的应用增加了 TM (3.5 K/GPa) 并稳定了马氏体相。对于 Ni1.8Pt0.2MnGa 在环境压力下 9 T 的场变化，观察到 9.31 J Kg-1 K-1 的最大磁熵变化 (ΔSmax)。更多，