粒径与掺杂对ZrO_2纳米粉相结构的影响

EFFECT OF CRYSTALLITE SIZE AND DOPANTS ON PHASE STRUCTURE OF ZrO_2 NANOPOWDERS

用Ｘ射线衍射仪和透射电镜研究了粒径和Ｙ，Ｃｅ掺杂元素对ＺｒＯ２纳米粉相结构的影响．结果表明，在室温下平均粒径为～１０ｎｍ的ＺｒＯ２粉单斜相不足２０ｖ．％，而加入２ｍｏｌ％Ｙ２Ｏ３或２ｍｏｌ％ＣｅＯ２可使单斜相更少．试验测得纯ＺｒＯ２，ＺｒＯ２－２ｍｏｌ％ＣｅＯ２，ＺｒＯ２－２ｍｏｌ％Ｙ２Ｏ３纳米粉在室温下单斜相和四方相保持平衡共存的临界粒径分别为１７．５，２１．０和３２．５ｎｍ．

The effect of crystallite size and Y. Ce dopants on phase structure of nano-sized ZrO2 powders has been investigated by XRD and TEM methods. The results show that the volume fraction of m phase is less than 20% at room temperature for pure Zro2 powder with about 10 nm in average diameter. Adding 2mol% CeO2 or 2mol% Y2O2 to ZrO2 could make m phase further reduced. The critical grain sizes for pure Zro2, ZrO2-2mol% CeO2 and ZrO2-2mol%Y2O3 powders are estimated respectively at 17.5, 21 .0 and 32.5 nm according to XRD result. if the particle sizes in the powders are in normal distribution. When the particles are less than the critical size. the t phase can be stable at room temperature.