组成敏感性和一、二、三体相互作用在玻璃形成合金中的作用：CuZr 与 NiAl。

Composition susceptibility and the role of one, two, and three-body interactions in glass forming alloys: CuZr vs NiAl.

机构信息

School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.

School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia.

出版信息

J Chem Phys. 2018 Jun 14;148(22):224502. doi: 10.1063/1.5025203.

DOI:10.1063/1.5025203

PMID:29907012

Abstract

In this paper, we compare the composition fluctuations and interaction potentials of a good metallic glass former, CuZr, and a poor glass former, NiAl. The Bhatia-Thornton correlation functions are calculated. Motivated by the observation of chemical ordering at the NiAl surface, we derive a new property, R^(q), corresponding to the linear susceptibility of concentration to a perturbation in density. We present a direct comparison of the potentials for the two model alloys using a 2nd order density expansion, and establish that the one-body energy plays a crucial role in stabilizing the crystal relative to the liquid in both alloys but that the three-body contribution to the heat of fusion is significantly larger in NiAl than CuZr.

摘要

在本文中，我们比较了一种良好的金属玻璃形成体 CuZr 和一种较差的玻璃形成体 NiAl 的组成波动和相互作用势。计算了 Bhatia-Thornton 相关函数。受 NiAl 表面化学有序观察的启发，我们推导出了一个新的性质 R^(q)，它对应于浓度对密度扰动的线性响应。我们使用二阶密度展开直接比较了两种模型合金的势，并确定在两种合金中，单体能量在稳定晶体相对于液体方面起着至关重要的作用，但 NiAl 中对熔化热的三体贡献明显大于 CuZr。