中文摘要：

根据Zr-Fe-Nb体系中Laves_C15结构金属间化合物可能的成分范围熔炼合金铸锭,酸洗除氧化膜后经580℃/50 h退火处理获得单相合金试样,借助TEM＆SAD,EDS,XRD和Rietveld结构精修等方法获取Laves_C15结构金属间化合物的晶体学信息。TEM＆SAD结果表明,合金相具有面心立方结构。EDS分析表明,xZr/（xFe＋xNb）≈1/2,xNb/（xFe＋xNb）≈12%～17%,合金相化学式可表示为Zr1＋δ（Fe1-xNbx）2,其中,-0.16〈δ〈0.05,0.12〈x〈0.17。实测XRD谱图所有衍射峰位与面心立方结构化合物ZrFe2（标准卡片,No.38-1169）的峰位基本一致,高角度衍射峰较标准ZrFe2峰位有所偏移,说明有部分Nb固溶。Rietveld结构精修得到的计算图谱与实测图谱的峰形与峰位拟合良好,可信度因子Rp=0.186,Rwp=0.152,Rexp=0.1016,RB=0.04479,S=1.496。精修得出合金相晶格常数为0.702283（8）nm,Nb进入16d的位置取代Fe,且Nb进入16d位置占位分数约为13%,与TEM结果（12%～17%）一致。此化合物可表示为Zr（FeNb）2。

英文摘要：

An alloy with Laves_C15 single phase in the Zr-Fe-Nb system was prepared by vacuum smelting and heat treatment processes of 580 ℃/50 h after acid pickling to remove the oxide film.Crystal structural parameters for the compound were obtained using TEMSAD,EDS,XRD and Rietveld refinement method.TEMSAD results showed that the alloy sample was with face-centered cubic structure.EDS analysis indicated that the alloy sample was with the compositions of xZr/（xFe＋xNb）≈1/2,and xNb/（xFe＋xNb）≈12% ~17%.The formula for the compound could be expressed as Zr1＋δ（Fe1-xNbx）2,where-0.16δ0.05 and 0.12x0.17.The experimental XRD pattern was similar to that of ZrFe2 with face-centered cubic structure（standard reference PDF card,No.38-1169）.Compare to the standard pattern of ZrFe2,shifts of the peaks centered on high-angle were observed might be caused by the solution of Nb.The calculated pattern using Rietveld refinement method agreed well with the experimental pattern,including shapes and peak positions.The reliability factors were Rp=0.186,Rwp=0.152,Rexp=0.1016,RB=0.04479,S=1.496.The results also showed that Nb replaced Fe and entered into 16d site,and its occupancy fraction was around 13%,which was consistent with the results of TEM（12% ~17%）.This compound could be formulized as Zr（FeNb）2.