纳米晶LaCoO_3的界面缺陷研究

STUDY ON DEFECTS OF INTERFACE IN LaCoO_3 NANOCRYSTALS

用草酸盐共沉淀法 ,结合不同干燥条件 ,得到了氧空位较多的纳米晶 La Co O3钙钛矿。用正电子湮没寿命谱研究了氧空位较多的纳米晶 La Co O3催化剂的界面结构。结果表明 :纳米晶 La Co O3的聚集体微结构主要由两部分组成——含有氧空位的结晶晶粒以及晶界表面 ,基本上不存在由多个晶粒围成的大孔穴。不同的干燥条件可制备得到不同晶粒度和不同大小氧空位的 La Co

A series of LaCoO 3 perovskite nanocrystals were prepared by oxalate coprecipitation method, under different drying conditions. The structure of interface of LaCoO 3 catalyst with more of oxygen vacancy was studied by positron annihilation technique (PAT). The results indicated that the microstructure of LaCoO 3 nanocrystals are mainly composed by crystalline particles with oxygen vacancy and its interface. Big cavities around by more crystalline particles are not existed mainly. The different characteristic LaCoO 3 perovskites were made by changed drying conditions.