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利用XAFS和XRD方法分别研究了机械合金化 80h制备的Fe10 0 -xCux系统的晶体结构及Fe和Cu原子的局域配位环境 .结果表明 ,当x>4 0时 ,样品中Fe原子的bcc结构消失 ,Cu原子的近邻结构基本不变 ,fcc晶格参数随x的增加而减小 ;当x <30时 ,Cu原子的fcc结构消失 ,Fe原子的近邻结构基本不变 ,bcc晶格参数随Cu原子的比例减小而增大 ;而x=30左右时 ,fcc和bcc结构共存 .研究结果还表明 ,Fe原子和Cu原子的比例不是相差很大时 ,Fe原子和Cu原子的近邻配位无序度会在很大的范围内变化 ,说明Fe -Cu二元体系不可能形成均匀的过饱和固溶体 ,存在Cu富集区和Fe富集区 ,是由多种物态组成的混合物
The crystal structure of Fe10 0-xCux system prepared by mechanical alloying and the local coordination environment of Fe and Cu atoms were investigated by X-ray diffraction and X-ray diffraction. The results show that when x> 40, the bcc The near-neighbor structure of Cu atom remains unchanged and the lattice parameter of fcc decreases with the increase of x. When x <30, the fcc structure of Cu atom vanishes and the near-neighbor structure of Fe atom remains unchanged. The lattice parameter of bcc With the decrease of the Cu atomic ratio, the coexistence of fcc and bcc structures coexist when the ratio of Cu atoms decreases. The results also show that the close proximity of Fe atoms and Cu atoms is not significant when the ratio of Fe atoms to Cu atoms is not very different Bit degree of disorder will vary within a large range, indicating Fe Cu binary system can not form a uniform supersaturated solid solution, there is Cu enrichment and Fe enrichment zone, is composed of a mixture of a variety of states