金属玻璃与应变玻璃的动力学共性特征的研究

The study on the dynamic properties of glass is the key to understand the nature of glass and the mechanism of glass property control. In metallic materials, besides the metallic glass caused by the disordered arrangement of atoms, there is a new glassy phenomenon: strain glass in shape memory alloys, which is caused by the disordered distribution of strain (the order parameter of martensitic transformation). In metallic glasses, a series of dynamic properties has been found, such as α relaxation, β relaxation, boson peak and so on. In strain glasses, however, only the dynamic relaxation around the glass transition temperature is discovered (in analogy to α relaxation in metallic glass). Thus, the understanding on the dynamic properties of strain glass is still limited, and the study on the common dynamic properties of these two glasses is also lacking..Here, based on our previous studies, we plans to systematically explore the dynamic properties of strain glass in much wider temperature and time scales, and investigate the relationship between dynamic properties and other properties, by drawing on the study methods and theoretical framework of dynamic characteristics of metallic glass. Then, we intends to find the common dynamic characteristics of these two glasses, and study the underlying physical mechanism, and establish a theoretical model finally. We hope our study may provide the theoretical basis for the design and development of new glassy materials.

关于玻璃的动力学特征的研究是理解玻璃的物理本质，进而理解玻璃性能的调控机制的关键。在金属材料中，除了由原子无序排列而形成的金属玻璃外，近年来还发现了一种新的玻璃现象：形状记忆合金中的由于应变（马氏体相变的序参量）无序分布而形成的应变玻璃。在金属玻璃中，人们发现了α弛豫、β弛豫以及玻色峰等一系列动力学特征。然而，对于应变玻璃，人们目前却仅仅发现了在玻璃转变温度附近的弛豫现象（对应于α弛豫）。因此，目前关于应变玻璃的动力学特征的研究还十分有限，而有关两种玻璃的动力学共性特征的研究仍是空白。.本项目拟在前期的研究基础上，借鉴金属玻璃动力学特征的研究方法和理论框架，在尽量宽的温度和时间窗口下系统研究应变玻璃的动力学特征，并力图找到其动力学特征与其他性能之间的内在联系；之后提炼两种玻璃的动力学共性特征，并寻找共性特征背后的物理规律和建立相应的理论模型；从而为新型玻璃态材料的设计和开发提供理论依据。

在金属材料中，不但存在着由于原子排列无序而形成的金属玻璃，而且还存在着由于相变应变（马氏体相变的序参量）无序分布而形成的应变玻璃合金。金属玻璃的动力学特征对理解其物理本质起到了举足轻重的作用，而关于应变玻璃的动力学特征的研究目前仍然很有限，而两种玻璃的动力学特征的共性与差异仍然是未解之谜。针对该问题，本项目在大量研究基础之上，发现了应变玻璃具有与金属玻璃的玻色峰类似的低温比热异常，并发现应变玻璃中的类玻色峰异常起源于一种新的机制——横波声学支的软化，进而发现了两种玻璃态中玻色峰的不同的机制在一个基于格林函数的理论模型中具有统一性；发现了两个具有高玻璃转变温度的应变玻璃合金体系，并系统研究了一个三元应变玻璃合金的相图，验证了应变玻璃的玻色峰的普遍性等。该项目的成果为理解玻璃的物理本质及不同玻璃态之间的共性特征提供了新的视角。