用X射线衍射(XRD),电子衍射(ED),透射电镜(TEM)和X射线电子能谱(EDAX)方法研究用惰性气体凝聚法制备的Fe_(50)Pd_(50)合金超微粒子(UFP)的X射线衍射峰宽化机制,结果表明其反常宽化是由于合金粒子间的成分不均匀引起的成分宽化量与衍射角θ和成分不均匀而引起的平均晶格常数变化率e_c有关,可表示为:川Gaussian,Cauchy和混合线形计算了平均粒径,Cauchy和混合线形得到的结果与电镜观测值符合较好当粒径较小时,由各种线形算出的结果比较相近,它们之间的差异随着粒径增大而增大,
The mechanism of X-ray diffraction peak broadening of Fe_(50)Pd(50) alloyultrafine particles(UFP), produced by inert gas condensation method, has been investigatedby XRD, ED, TEM and EDAX. The results show that the anomalous peak broadening of thealloy UFP is caused by the nonuniformity in chemical composition. The composition broad-ening factor is decided by the diffraction angle θ and the average variation rate of the latticeparamater e_c which is caused by composition nonuniform. It can be expressed by the formulaβ_c(2θ)=4e_ctanθMean particle size is calculated by using Gaussian, Cauchy and mixed profiles. UsingCauchy or mixed profiles can lead to a better agreement with the TEM results. The results ob-tained from various profiles are close to each other when particle size is small. The discrepan-cy becomes large with the increase in particle size.
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