Microdomain atomic structure of Zr_(50)Pd_(40)Al_(10) metallic glasses and its formation mechanism

作     者：Kai Li Fangliang Gao Yu-Jen Chou Kaixiang Shen Guoqiang Li 

作者机构：State Key Laboratory of Luminescent Materials and Devices South China University of Technology Engineering Research Center on Solid-State Lighting and Its Informationisation of Guangdong Province South China University of Technology Department of Electronic Materials School of Materials Science and Engineering South China University of Technology School of Physics and Telecommunications Engineering South China Normal University 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2019年第35卷第3期

页      面：248-253页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by National Science Fund for Excellent Young Scholars of China (No. 51422203) the National Natural Science Foundation of China (Nos. 51572091 and 51372001) the Natural Science Foundation of Guangdong Province, China (No. 2018A030313395) the China Postdoctoral Science Foundation (No. 2017M610522) the Science and Technology Program of Guangzhou, China (No. 201604046027) the Fundamental Research Funds for the Central Universities (No. 2017BQ035) the fund of the State Key Laboratory of Solidification Processing in NWPU (No. SKLSP201716) 

主　　题：Metallic glasses Radial distribution function Electron diffraction Density functional theory Formation mechanism 

摘      要：Zr-based Zr_50Pd_40Al_10 metallic glasses has not only crystalline phases of about 5 nm in diameter but also amorphous phases. In this work, the radial distribution functions(RDFs) of amorphous structure of Zr_50Pd_40Al_10 metallic glasses were firstly measured by electron diffraction, and then Reverse Monte Carlo(RMC) optimization accompanied by density functional theory(DFT) calculations. The amorphous structure has not only short-range order but also good medium-range order. In the RDFs of its amorphous structure, the first and the second peaks are located at 2.96 ? and 4.79 ?, respectively. Partial radical distribution functions(PRDFs) show that the contributions of the first and the second nearest-neighbor distances of various atom pairs to the G(r) peak values, and the first nearest-neighbor distances of Pd–Zr and Zr–Zr atom pairs are the sources of main G(r) peak values between 2? and 6?. The competition mechanism for generating the Pd_25Zr_55 Al_20 amorphous phase and the intermetallic crystalline phase Pd_11Zr_9 is associated with the differences of atomic radius, the proportion, and the melting point of different atoms, as well as the heat of mixing between atoms, leading to an equilibrium state of the two phases. Accordingly, a composite system with intertwined nanocrystals and amorphous phases is in turn formed, and improves the stability of the material.