Li Dongdong, Chen Heng, Qu Bingyan, Zhang Fabao, Zhou Rulong, Zhang Bo
Engineering Research Center of High Performance Copper Alloy Materials and Processing, Ministry of Education, Hefei University of Technology, Hefei 230009, China.
School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230009, China.
Phys Chem Chem Phys. 2021 Jan 21;23(2):982-989. doi: 10.1039/d0cp05327a.
In this study, intensive calculations were performed to investigate the behavior of the low-temperature excess heat capacity of Cu50Zr50 ultrathin film metallic glasses. Our results show that there is a well-defined boson peak in the film metallic glasses and that the boson peak height exhibits an obvious size-dependent feature. Furthermore, there is a critical thickness dc in the curves between the boson peak height and the thickness, where the boson peak height changes abruptly. Through structural analysis, we found that the low-temperature excess heat capacity of the film metallic glasses is correlated with the density layering structure near the surface. The structural parameter S is defined by atomic density and it was found that the boson peak height is highly correlated with S. Our investigation of ultrathin film metallic glasses provides a deeper understanding about the structural origin of the boson peak in metallic glasses.
在本研究中，进行了密集计算以研究Cu50Zr50超薄膜金属玻璃的低温过剩热容量行为。我们的结果表明，在薄膜金属玻璃中存在一个明确的玻色子峰，并且玻色子峰高度呈现出明显的尺寸依赖特征。此外，在玻色子峰高度与厚度的曲线中存在一个临界厚度dc，在该厚度处玻色子峰高度会突然变化。通过结构分析，我们发现薄膜金属玻璃的低温过剩热容量与表面附近的密度分层结构相关。结构参数S由原子密度定义，并且发现玻色子峰高度与S高度相关。我们对超薄膜金属玻璃的研究为深入理解金属玻璃中玻色子峰的结构起源提供了帮助。
