Kuznetsov D D, Kuznetsova E I, Mashirov A V, Loshachenko A S, Danilov D V, Mitsiuk V I, Kuznetsov A S, Shavrov V G, Koledov V V, Ari-Gur P
Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, 125009 Moscow, Russia.
M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia.
Nanomaterials (Basel). 2023 Apr 16;13(8):1385. doi: 10.3390/nano13081385.
NiMnIn (close to 2-1-1 system) Heusler alloy was studied by magnetization measurement dependence on the temperature in magnetic fields of up to 13.5 T. The magnetocaloric effect measured by the direct method in quasi-adiabatic conditions showed a maximum value of ∆T = -4.2 K at a temperature T = 212 K in a magnetic field of 10 T in the region of martensitic transformation. The structure of the alloy was studied by transmission electron microscopy (TEM) as a function of the temperature and the thickness of the sample foil. In the temperature range from 353 to 215 K, at least two processes were established. The results of the study indicate that the concentration stratification occurs according to the mechanism of spinodal decomposition (conditionally spinodal decomposition) into nanoscale regions. At a temperature of 215 K and lower, martensitic phase with 14 M modulation is observed in the alloy at thicknesses greater than 50 nm. Some austenite is also observed. In foils with thickness of less than 50 nm in a temperature range from 353 to 100 Km only the initial austenite, which has not transformed, was found.
研究了接近2-1-1体系的NiMnIn赫斯勒合金在高达13.5 T磁场中随温度变化的磁化测量情况。在准绝热条件下用直接法测量的磁热效应表明，在马氏体转变区域，于10 T磁场中温度T = 212 K时，∆T = -4.2 K出现最大值。通过透射电子显微镜（TEM）研究了合金结构随温度和样品箔厚度的变化。在353至215 K的温度范围内，至少确定了两个过程。研究结果表明，浓度分层是根据旋节分解（条件性旋节分解）机制发生的，形成纳米级区域。在215 K及更低温度下，在厚度大于50 nm的合金中观察到具有14 M调制的马氏体相。还观察到一些奥氏体。在厚度小于50 nm的箔片中，在353至100 K的温度范围内，仅发现了未转变的初始奥氏体。
