Abstract The complete martensitic transformation sequence and magnetic properties of the non-stoichiometric Ni2Mn1.2Ga0.8 alloy have been revealed by the first-principles calculations. The calculated martensitic transformation sequence of the Ni2Mn1.2Ga0.8 alloy during cooling is Paramagnetic Austenite (PA) → Ferromagnetic Austenite (FA) → 7M → NM, which is consistent with the experimental observations. When the cubic FA phase transforms to a 7M or NM martensitic phase, a significant reduction of the down-spin total density of states occurred at the Fermi level. This makes the martensitic phase more stable than the FA phase at low temperature.

中文翻译：

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非化学计量Ni2Mn1.2Ga0.8合金的第一性原理计算完整的马氏体相变序列和磁性能

摘要 通过第一性原理计算揭示了非化学计量Ni2Mn1.2Ga0.8合金的完整马氏体相变序列和磁性能。Ni2Mn1.2Ga0.8合金冷却过程中计算出的马氏体相变顺序为顺磁奥氏体（PA）→铁磁奥氏体（FA）→7M→NM，与实验观察一致。当立方 FA 相转变为 7M 或 NM 马氏体相时，在费米能级处发生了下旋总态密度的显着降低。这使得马氏体相在低温下比 FA 相更稳定。