Ren Shuai, Zong Hong-Xiang, Tao Xue-Fei, Sun Yong-Hao, Sun Bao-An, Xue De-Zhen, Ding Xiang-Dong, Wang Wei-Hua
Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China.
Nat Commun. 2021 Oct 1;12(1):5755. doi: 10.1038/s41467-021-26029-w.
Strain glass is a glassy state with frozen ferroelastic/martensitic nanodomains in shape memory alloys, yet its nature remains unclear. Here, we report a glassy feature in strain glass that was thought to be only present in structural glasses. An abnormal hump is observed in strain glass around 10 K upon normalizing the specific heat by cubed temperature, similar to the boson peak in metallic glass. The simulation studies show that this boson-peak-like anomaly is caused by the phonon softening of the non-transforming matrix surrounding martensitic domains, which occurs in a transverse acoustic branch not associated with the martensitic transformation displacements. Therefore, this anomaly neither is a relic of van Hove singularity nor can be explained by other theories relying on structural disorder, while it verifies a recent theoretical model without any assumptions of disorder. This work might provide fresh insights in understanding the nature of glassy states and associated vibrational properties.
应变玻璃是形状记忆合金中具有冻结铁弹性/马氏体纳米畴的玻璃态，但其本质仍不清楚。在此，我们报道了应变玻璃中一种被认为仅存在于结构玻璃中的玻璃态特征。在将比热按温度立方归一化后，在约10K的应变玻璃中观察到一个异常峰，类似于金属玻璃中的玻色子峰。模拟研究表明，这种类似玻色子峰的异常是由马氏体畴周围非转变基体的声子软化引起的，它发生在与马氏体转变位移无关的横向声学支中。因此，这种异常既不是范霍夫奇点的遗留物，也不能用其他依赖结构无序的理论来解释，同时它验证了一个没有任何无序假设的近期理论模型。这项工作可能为理解玻璃态的本质及相关振动特性提供新的见解。
