The transition sequence in the Heusler alloy Ni50Mn34In8Ga8 has been determined from measurements of elasticity, heat flow and magnetism to be paramagnetic austenite → paramagnetic martensite → ferromagnetic martensite at ~335 and ~260 K, respectively, during cooling. The overall pattern of elastic stiffening/softening and acoustic loss is typical of a system with bilinear coupling between symmetry breaking strain and the driving order parameter in a temperature interval below the transition point in which ferroelastic twin walls remain mobile under the influence of external stress. Divergence between zero-field-cooling (ZFC) and field-cooling (FC) determinations of DC magnetisation below ~220 K indicates that a frustrated magnetic glass develops in the ferromagnetic martensite. An AC magnetic anomaly which shows Vogel-Fulcher dynamics in the vicinity of ~160 K is evidence of a further glassy freezing process. This coincides with an acoustic loss peak and slight elastic stiffening that is typical of the outcome of freezing of ferroelastic twin walls. The results indicate that local strain variations associated with the ferroelastic twin walls couple with local moments to induce glassy magnetic behaviour.

中文翻译：

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Heusler 合金 Ni50Mn34In8Ga8 中相变与玻璃态磁行为的耦合


根据弹性、热流和磁性测量，Heusler 合金 Ni50Mn34In8Ga8 的转变顺序分别在~335 K 和~260 K 冷却过程中确定为顺磁性奥氏体 → 顺磁性马氏体 → 铁磁性马氏体。弹性硬化/软化和声学损失的总体模式是在低于转变点的温度区间内对称破断应变和驱动阶次参数之间具有双线性耦合的系统的典型特征，其中铁弹性双壁在外部应力的影响下保持移动。直流磁化强度低于约 220 K 的零场冷却 (ZFC) 和场冷却 (FC) 测定结果之间的差异表明，铁磁马氏体中形成了受挫磁性玻璃。交流磁异常显示约 160 K 附近的 Vogel-Fulcher 动力学，这是进一步玻璃态冻结过程的证据。这与声学损失峰值和轻微的弹性硬化相一致，这是铁弹性双壁冻结的典型结果。结果表明，与铁弹性双壁相关的局部应变变化与局部力矩耦合，从而诱发玻璃磁行为。