ZrO_2-6Y_2O_3陶瓷中的类L1_2与L1_0有序结构

L12 AND L10-LIKE ORDERED STRUCTURE IN ZrO2-6Y2O3 CERAMICS

采用高分辨电子显微术（ＨＲＥＭ）、能量散射Ｘ射线谱（ＥＤＸＳ）及计算机模拟的方法，研究了烧结态与时效后的ＺｒＯ２－６Ｙ２Ｏ３（摩尔分数，％）陶瓷中发现的分别具有类Ｌ１２与类Ｌ１０有序结构的Ｙ０．２５Ｚｒ０．７５Ｏ２－ｘ与Ｙ０．５ｒ０．５Ｏ２－ｙ相．结果表明，两种新相形成于烧结过程，其含量随时效温度升高及时效时间延长而有所增加．试样不同区域中Ｙ元素的偏聚是导致Ｙ０．２５Ｚｒ０．７５Ｏ２－ｘ及Ｙ０．５Ｚｒ０．５Ｏ２－ｙ相形成的原因．Ｙ元素的偏聚机理是烧结和时效过程中的热扩散．

Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases with L12 and L10-like ordered structures,respectively,in ZrO2-6Y2O3 (mole fraction,%) ceramics as both sintered and annealed states have beenfound by high-resolution electron microscopy (HREM), energy-dispersive X-ray spectroscopy (EDXS) andcomputer simulation. The formation of Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases initiates in the sinteringprocedure and develops with increasing the annealing temperature and time. Segregation of yttrium, whichis prevalent in different regions of the samples, induces the formation of Y0.25Zr0.75O2-x. and Y0.5Zr0.5O2-yphases.