通过热力学等计算得出AgSnO2材料中SnO2颗粒的临界形核半径等数据,以此为依据对反应合成法制备AgSnO2材料过程中SnO2颗粒的形核以及生长机制进行分析。结果表明:SnO2颗粒在成长过程中受到基体中Sn元素扩散以及基体颗粒尺寸因素的控制。反应合成法制备的AgSnO2材料中SnO2颗粒的尺寸大多处在约50nm直径的范围,部分区域中由于Sn的缺陷扩散影响,出现了尺度在200nm左右的较大SnO2颗粒,由于最后一批形核的SnO2颗粒缺乏Sn的补充,所以反应合成法制备的AgSnO2材料中存在直径在10nm左右的纳米级SnO2颗粒。
The critical radius of nucleus of SnO2 particulate in AgSnO2 composite are calculated by Thermodynamics. The nucleation and growth mechanisms of SnO2 particulates in AgSnO2 composite prepared by reactive synthesis process were analyzed based on these dates. The results shown that growth of SnO2 particulates was affected by the diffusion of tin atom in alloy and particle size of initial raw materials. The dimension of SnO2 particulates were about 50 nm, and some SnO2 of about 200 nm in particle size also appeared because of the defective diffusion of tin atoms. The particle size of SnO2 formed from the last nuclei was about 10 nm in diameter due to lack supply of tin atoms.