Local atomic structure of Pd-Ni-P bulk metallic glass examined by high-resolution electron microscopy and electron diffraction
Local atomic structure of Pd-Ni-P bulk metallic glass examined by high-resolution electron microscopy and electron diffraction
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DOI：
10.1016/j.intermet.2006.01.007
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发表时间：
2006-08-01
期刊：
影响因子：
4.4
通讯作者：
Nieh, T. G.
中科院分区：
文献类型：
--
作者：
Hirata, Akihiko;Hirotsu, Yoshihiko;Nieh, T. G.
用透射电镜和电子衍射研究了Pd 40 Ni 40 P20大块金属玻璃的结构涨落。局部原子有序区域与fcc-（Pd，Ni）型结构的清晰成像的高分辨电子显微镜（HREM）附加Cs-校正。玻璃态的干涉函数是由电子衍射强度分布，使用能量过滤器和成像板技术。我们使用了反向蒙特卡罗（RMC）模拟方法来开发一个现实的结构模型。该模型由一个稠密的随机包装结构，其中一个收费有序区域与Pd。Ni和P原子嵌入。结构模型与衍射和高分辨电子显微镜的结果一致。在Voronoi多面体分析的RMC模拟结构，P-中心的（Pd，Ni）-P三角棱镜被发现主要嵌入fcc集团的矩阵结构。在Pd和Ni原子周围经常观察到变形的fcc型多面体。从这些局部的结构特征，纳米级的相分离被揭示在玻璃形成过程中发生。(c)2006爱思唯尔有限公司版权所有。
Structural fluctuation in a Pd40Ni40P20 bulk metallic glass is investigated by transmission electron microscopy and electron diffraction. Local atomic ordered regions with a fcc-(Pd,Ni) type structure was sharply imaged by a high-resolution electron microscopy (HREM) attached with a Cs-corrector. Interference function for the glassy state was obtained from electron-diffraction intensity profiles using energy-filter and imaging-plate techniques. We used a reverse Monte Carlo (RMC) simulation method to develop a realistic structure model. The model consists of a dense-random-packing structure, in which an fee ordered region with Pd. Ni, and P atoms was embedded. The structure model is consistent with the diffraction and HREM results. In Voronoi polyhedral analysis of the RMC simulated structure, P-centered (Pd,Ni)-P trigonal prisms are found primarily in the matrix structure embedding the fcc-cluster. Around Pd and Ni atoms deformed-fcc type polyhedra were frequently observed. From these local structural features, nanoscale phase separation was revealed to occur during the glass formation. (c) 2006 Elsevier Ltd. All rights reserved.