摘要
以紫外拉曼光谱技术研究了在不同焙烧气氛中氧化锆样品的表面晶相结构及其转变过程 .结果表明 ,在有氧气氛中焙烧的氧化锆样品易转变为单斜相 ,而在惰性气氛中焙烧可以有效地稳定样品体相和表面的四方相结构 .在缺氧气氛中焙烧的样品暴露于空气中后 ,表面极易转变为单斜相 ,而其体相仍为四方相结构 ,这表明四方相氧化锆在样品表面是极不稳定的 .
UV Raman spectroscopy has been employed to investigate the surface phase transf ormation of zirconia calcined at different temperatures in different atmosphere s. The calcination of samples in gas containing O 2 leads to the formation of the monoclinic phase, while the calcination in inert gas delays the formation of the crystal phase and benefits the stabilization of the tetragonal phase. Th e tetragonal phase in the surface region transforms easily to the monoclinic pha se when the samples are exposed to air, indicating that the tetragonal phase is prone to be unstable in the surface region of the samples. It is possible that oxygen vacancies formed in the surface region in the absence of oxygen can prev ent the transformation from the tetragonal phase to the monoclinic phase. When t he samples are exposed to air, the elimination of these vacancies by the incorpo ration of oxygen facilitates the transformation from the tetragonal phase to the monoclinic phase.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第11期861-866,共6页
基金
国家自然科学基金资助项目( 2 0 2 73 0 69
2 0 3 73 0 69)
国家重点基础研究发展规划项目(G19990 2 2 40 7)
关键词
紫外拉曼光谱
氧化锆
焙烧气氛
相变
表面
UV Raman spectroscopy, zirconia, calcination atmosphere, phase transformation, s urface
