Atomic structures of Zr-based metallic glasses  

作　　者：HUI XiDong LIU XiongJun GAO Rui HOU HuaiYu FANG HuaZhi LIU ZiKui CHEN GuoLiang 

机构地区：[1]State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China [2]Department of Materials Science and Engineering,Nanjing University of Science and Technology,Nan-jing 210014,China [3]Department of Materials Science and Engineering,Pennsylvania State University,University Park,PA 16802,USA

出　　处：《Science China(Physics,Mechanics & Astronomy)》2008年第4期400-413,共14页中国科学：物理学、力学、天文学（英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 50431030 and 50471097);the National Basic Research Program of China (Grant No. 2007CB613901);the Programme of Introducing Talents of Discipline to Universities (Grant No. B07003)

摘　　要：The atomic structures of Zr-Ni and Zr-Ti-Al-Cu-Ni metallic glasses were investigated by using classical molecular dynamic (MD),reverse Monte Carlo (RMC),ab initio MD (AIMD) simulations and high resolution transmission electron microscopy (HRTEM) techniques. We focused on the short-range order (SRO) and medium-range order (MRO) in the glassy structure. It is shown that there are icosahedral,FCC-and BCC-type SROs in the Zr-based metallic glasses. A structural model,characterized by imperfect ordered packing (IOP),was proposed based on the MD simulation and confirmed by the HRTEM observation. Furthermore,the evolution from IOP to nanocrystal during the crystallization of metallic glasses was also ex-plored. It is found that the growth from IOP to nanocrystal proceeds through three distinct stages: the formation of quasi-ordered structure with one-dimensional (1D) periodicity,then 2D periodicity,and finally the formation of 3D nanocrystals. It is also noted that these three growth steps are crosslinked.The atomic structures of Zr-Ni and Zr-Ti-Al-Cu-Ni metallic glasses were investigated by using classical molecular dynamic (MD), reverse Monte Carlo (RMC), ab initio MD (AIMD) simulations and high resolution transmission electron microscopy (HRTEM) techniques. We focused on the short-range order (SRO) and medium-range order (MRO) in the glassy structure. It is shown that there are icosahedral, FCC-and BCC-type SROs in the Zr-based metallic glasses. A structural model, characterized by imperfect ordered packing (IOP), was proposed based on the MD simulation and confirmed by the HRTEM observation. Furthermore, the evolution from IOP to nanocrystal during the crystallization of metallic glasses was also explored. It is found that the growth from IOP to nanocrystal proceeds through three distinct stages: the formation of quasi-ordered structure with one-dimensional (1D) periodicity, then 2D periodicity, and finally the formation of 3D nanocrystals. It is also noted that these three growth steps are crosslinked.

关 键 词：METALLIC GLASSES ATOMIC structure SHORT-RANGE order medium-range order molecular dynamics REVERSE MONTE Carlo 

分 类 号：O562.1[理学—原子与分子物理]