水热合成中负离子配位多面体生长基元模型与粉体的晶粒粒度

GROWTH UNIT MODEL OF ANION COORDINATION POLYHEDRON AND THE PARTICLE SIZE OF POWDERS IN THE HYDROTHERMAL FORMATION

在负离子配位多面体生长基元模型的基础上深入研究了晶粒的结晶过程．认为成核过程主要包括生长基元的形成和生长基元之间的脱水反应过程，并从成核速度的角度分析了影响晶粒粒度的主要原因．揭示了影响晶粒粒度的主要原因为生长基元的生成能、晶体的晶格能．由此总结出不同结构类型的氧化物粉体晶粒粒度的相对大小．合理地解释了由水热法制得的氧化物粉体的晶粒粒度差别较大的原因以及反应介质、反应温度对晶粒粒度的影响．

The crystallization process is investigated on the basis of growth unit model of anion coordination polyhedron. It can be concluded that the idealized nucleation process consists of the formation of growth unit and the dehydration reaction between growth units. The main factors affecting particle size are analyzed from the view of the rate of nucleation. It is revealed that the formation energy of growth unit and crystal lattice energy are the main factors affecting particle size. The relative particle size sequence of oxide powder with different structure types is obtained. The difference of particle size of various kinds of oxide powder prepared by hydrothermal method and the effects of reaction medium and reaction temperature on the particle size are reasonably explained.