Experiments in X-ray Crystallography: Rare Earth Elements in Titanite, Disorder in LaNi5-ySny Intermetallics, and Rare Earth Elements in Naturally-Occurring Perovskites

9627222 Hughes本研究将通过精确的衍射数据表征化学取代的性质。该项目包括三个任务：在钛铁矿中掺入稀土元素，LaNi 5-ySny的高精度单晶和Rietveld研究，以及天然钙钛矿相中的稀土元素。在钛铁矿中特别感兴趣的是REE的容纳和伴随的Ca+2（REE+3）交换的电荷平衡取代。金属间化合物，如掺杂有不同量的Sn的LaNi 5，正处于激烈的多学科研究中，用作H燃料和高性能电池电极的混合主体。高精度的晶体结构研究调查的无序相作为SN取代镍。将进行原子排列的Rietveld分析，以克服钙钛矿中普遍存在的孪生现象，这会减轻单晶方法的溶解/细化。

9627222 Hughes This study will characterize the nature of chemical substitutions by precise diffraction data. The project involves three tasks: incorporation of REE in titanite, high-precision single crystal and Rietveld studies of LaNi5-ySny hydrides, and REE in naturally-occurring perovskite phases. Of particular interest in titanite is the accommodation of REE's and the concomitant charge-balancing substitution for the Ca+2 ( REE+3 exchange. Intermetallic compounds such as LaNi5 doped with varying amounts of Sn, are under intense multi-disciplinary investigation for use as hybrid hosts for H fuels and electrodes in high-performance batteries. High-precision crystal structure studies investigate the disorder in the phase as SN substitutes for Ni. Rietveld analysis of the atomic arrangements will be undertaken to overcome the pervasive twinning in perovskites that mitigates against solution/refinement by single crystal methods.