论文标题
形状内存的可逆绝热温度变化Heusler Alloy Ni2.2Mn0.8GA：结构兼容性的效果
Reversible adiabatic temperature change in the shape memory Heusler alloy Ni2.2Mn0.8Ga: An effect of structural compatibility
论文作者
论文摘要
在基于Ni-Mn的形状 - 记忆助母素合金中观察到的大磁化效应（MCE）使它们可以用于磁制冷技术。它与一阶磁结构（马氏体）相变有关。我们对MCE进行了一项全面研究，用于远程计量的Heusler Alloy Ni $ _ {2.2} $ Mn $ _ {0.8} $ GA在其一阶磁结构相过渡的附近。我们在反复的磁场循环下发现了可逆的MCE。可逆行为可以归因于马氏体相变的小热滞后。基于对我们详细的温度依赖X射线衍射数据的分析，我们证明了Cubic Austenite和Tetragonal Martensite相的几何兼容性。这一发现将可逆的MCE行为直接与立方奥氏体和四方马氏体相之间改善的几何兼容性条件联系起来。该方法将有助于使用一阶马氏体相变的大量可逆MCE来设计形状内存啤酒合金。
The large magnetocaloric effect (MCE) observed in Ni-Mn based shape-memory Heusler alloys put them forward to use in magnetic refrigeration technology. It is associated with a first-order magnetostructural (martensitic) phase transition. We conducted a comprehensive study of the MCE for the off-stoichiometric Heusler alloy Ni$_{2.2}$Mn$_{0.8}$Ga in the vicinity of its first-order magnetostructural phase transition. We found a reversible MCE under repeated magnetic field cycles. The reversible behavior can be attributed to the small thermal hysteresis of the martensitic phase transition. Based on the analysis of our detailed temperature dependent X-ray diffraction data, we demonstrate the geometric compatibility of the cubic austenite and tetragonal martensite phases. This finding directly relates the reversible MCE behavior to an improved geometric compatibility condition between cubic austenite and tetragonal martensite phases. The approach will help to design shape-memory Heusler alloys with a large reversible MCE taking advantage of the first-order martensitic phase transition.
