Structure of eutectic liquids in the Au-Si, Au-Ge, and Ag-Ge binary systems by neutron diffraction
Structure of eutectic liquids in the Au-Si, Au-Ge, and Ag-Ge binary systems by neutron diffraction
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DOI：
10.1103/physrevb.83.014203
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发表时间：
2011-01-18
影响因子：
3.7
通讯作者：
Fischer, Henry E.
中科院分区：
文献类型：
--
作者：
Chirawatkul, Prae;Zeidler, Anita;Fischer, Henry E.
用中子衍射法研究了Au_(0.81)Si_(0.19)、Au_(0.72)Ge_(0.28)和Ag_(0.74)Ge_(0.26)三种液态合金的结构。对于给定的合金，在从5-6埃到超过20埃的很宽的距离上，测量的对分布函数由指数衰减的振荡函数描述，其衰减长度和振荡波长分别与总结构因子中主峰的半宽和主峰的位置有关。这种行为是从简单对位势的Ornstein-Zernike方程的解中预料到的。没有必要像最近对非晶态金属合金测量的衍射图的分析所表明的那样，引用分形网络的存在来解释实验结果。重新考虑这些非晶态合金的衍射数据也得出了同样的结论。
Neutron diffraction was used to investigate the structure of the liquid alloys Au0.81Si0.19, Au0.72Ge0.28, and Ag0.74Ge0.26 with composition at or near the eutectic. For a given alloy, the measured pair distribution function is described over a wide range of distances, from 5-6 angstrom to beyond 20 angstrom, by an exponentially damped oscillatory function with a decay length and wavelength of oscillation related to the half-width at half-maximum of the principal peak in the total structure factor and to the position of this peak, respectively. This behavior is expected from solutions of the Ornstein-Zernike equations for simple pair potentials. There is no need to invoke the existence of a fractal network, as suggested by a recent analysis of the diffraction patterns measured for amorphous metallic alloys, to account for the experimental results. A reconsideration of the diffraction data for these amorphous alloys points to the same conclusion.