氧化锡超微粒的纳米结构、化学稳定性与反常相变

Nanostructure,Chemical Stability and Abnormal Transformation in Ultrafine Particles of Oxidized Tin

采用低氧压下惰性气体沉积法制备粒经6nm以下的氧化锡微粒．由XRD、TEM及穆斯堡尔谱分析测定它的超精细参数、化学稳定性及加热过程发生的相变．结果表明，超微粒的纳米结构由体相和表面相组成；在室温下自发氧化形成稳定的二氧化锡．经300～600℃热处理后，产生正交与四方SnO2相．分析认为，正交SuO2相可能是在缺氧条件下，无序SnO2相向高温稳定四方相转变的中间产物．

Ultrafine oxidized tin particles with particle size about 6nm were prepared by inert gas con-desation deposition under low oxygen pressure. The nanostructure, hyperfine parameters and chemical stability were studied by means of TEM, XRD especially by Mossbauer spectra analysis.Results show that, the nanostructure of particles can be divided into crystal component and disor-der component. Nano-powders have high chemical activity and call be oxidezed into stable SnO2 compound at ambient temperature. XRD measurements show, post-annealing at temperature of 300-600℃ for 2h in air produces orthorhombic and tetragoual SnO2 phases. Orthorhombic SnO2 phase may be an intermediate phase while disorder SnO2 transforms to high temperature stable tetragoual SnO2 (rutile) under oxygen dencfency condition.