Abstract

We have assessed the informativeness of X-ray diffraction patterns in the form of a halo, characteristic of metallic alloys prepared by liquid quenching (melt spinning) (using an Fe₇₈P₂₀Si₂ alloy as an example) and oxide films grown on unheated substrates by ion beam sputtering of targets with an appropriate composition (LiNbO₃ and Ca₁₀(PO₄)₆(OH)₂). Simulation results for X-ray diffraction patterns of expected crystalline phases with allowance for the size effect in diffraction demonstrate that a model halo agrees well with the halos observed in X-ray diffraction patterns of the samples under study. Observed correlations lead us to conclude that, inherent in rather large crystals, coherence of elastically scattered waves is lost in the structures considered here because of the random mutual orientation of crystalline nuclei of the corresponding phases with ultimately small dimensions. For this reason, translational symmetry, limited by the ultimately small dimensions of mutually misoriented crystallites, is the most transparent characteristic of the nature of such (quasi-amorphous) structures for systems with strong interatomic bonding.

中文翻译：

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光晕形式的X射线衍射图的信息性

摘要

我们评估了光环形式的X射线衍射图的信息性，通过液体淬火（熔融纺丝）（以Fe ₇₈ P ₂₀ Si ₂合金为例）制备的金属合金的特性以及未加热时生长的氧化膜的特性通过离子束溅射对具有适当成分（LiNbO ₃和Ca ₁₀（PO ₄）₆（OH）₂）。预期的结晶相的X射线衍射图的模拟结果，考虑到衍射中的尺寸效应，表明模型晕与研究样品的X射线衍射图中观察到的晕非常吻合。观察到的相关性使我们得出结论，在相当大的晶体中，弹性散射波的相干性在此处考虑的结构中丢失了，这是因为相应相的晶核的最终尺寸很小，它们的相互随机取向。由于这个原因，平移对称性受相互错位的晶粒的最终小尺寸的限制，是这种（准非晶）结构的性质对于具有强原子间键合的系统而言最透明的特征。