LaF3薄片的液相合成和表征

Synthesis and Characterization of LaF3 Flakes Through a Solution-phase Approach

摘要: 在氨水或无水乙二胺体系中通过液相反应制备了单晶六方相LaF3薄片.用X射线衍射、透射电子显微镜、选区电子衍射、高分辨透射电子显微镜、X射线光电子能谱等对产物进行了表征.研究了反应时间对产物形貌的影响.结果表明，随着反应时间的延长，薄片尺寸变大.讨论了薄片生长的可能机理,当溶剂有配位作用时，如氨水或无水乙二胺，最初形成的LaF3沉淀溶解、重结晶，最终形成无规则的薄片；当溶剂无配位作用时，如四氯化碳或无水乙醇，最终产物为球形颗粒.

Abstract: Single-crystalline LaF3 flakes was synthesized through a facile solution-phase approach in aqueous ammonia and ethylenediamine. Applying the thermal treatment at 100 ℃ for 20 h, the LaF3 recrystallized, grew epitaxially and precipitated into flakes in aqueous ammonia or ethylenediamine. The formation of flakes could be attributed to the coordination effect of the solvent.