Zr48Cu45Al7大块金属玻璃的原子结构研究

应用同步辐射X射线衍射(XRD)和广延X射线吸收精细结构边方法(EXAFS),结合反蒙特卡罗(RMC)拟合、Voronoi分形技术等对Zr₅₀Cu₅₀二元和Zr₄₈Cu₄₅Al₇三元金属玻璃材料的微观结构进行了系统的研究.结果表明:ZrCuAl三元金属玻璃中Al原子与Zr原子、Cu原子之间存在强相互作用,表现为键长的明显缩短,导致其微观结构中的Voronoi团簇体积普遍小于Zr_{50关键词： 大块金属玻璃 原子结构 玻璃形成能力 同步辐射技术}

Atomic structure of Zr48 Cu45 Al7 bulk metallic glass

Atomic structures of Zr₄₈Cu₄₅Al₇ ternary and Zr₅₀Cu₅₀ binary metallic glasses were investigated by performing reverse Monte Carlo (RMC) simulation upon synchrotron radiation based X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) data. Bond shortening in Zr-Al and Cu-Al atomic pairs was detected in Zr₄₈Cu₄₅Al₇, which is attributed to strong interactions between Al atoms and its neighbors. Subsequently, their atomic structure was further analyzed by Voronoi tessellation method, it was found that all kinds of Voronoi clusters have smaller volume in Zr₄₈Cu₄₅Al₇ than their counterparts in Zr₅₀Cu₅₀. Accordingly it is suggested that atoms may be more densely packed in atomic structure of Zr₄₈Cu₄₅Al₇ ternary than in corresponding Zr₅₀Cu₅₀ binary MG at cluster scale, which may be the structural origin of high glass-forming ability of CuZr-based bulk metallic glass prepared by Al addition.