溶胶法合成ZrO_2（Y_2O_3）纳米晶超微粉研究

Sol Synthesis Preparation of Y_2O_3-DopedZrO_2 Nanocrystalline Powder

研究了水基溶胶法合成ＺｒＯ２（Ｙ２Ｏ３）纳米晶超微粉体的可能性。结果表明，这种方法能够合成粒径为数十至数个纳米的超微粉体，合成的粉体粒径分布均匀，分散性好。通过选择溶胶形成过程中前驱物浓度值，可以有效地控制合成的超微粉体的粒径，浓度增大，粉体粒径减小、合成的ＺｒＯ２（Ｙ２Ｏ３）粉体最小粒径为６ｎｍ，该值由溶胶中胶体粒子临界晶核的大小所决定。

Nanocrystalline powders as small as several urn in diameter have been reported in theopen literature but such extremely small powders, when obtained by chemical methods, cannot be controllably produced. In this paper we present our research results, whose one important finding (not the most important) is that powders of as small as 6 nm in diameter canbe controllably produced.More important than just produceng nm powders controllably, our method brings otheradvantages. Up to now, urn powders, as prepared by Sol-Gel process, must derive fromcorresponding metal alkoxides, which are poisonous and finite. Also Sol - Gel process iscomplicated and costly. These two severe disadvantages are eliminted when our method isused.Using inorganic precursor in Sol process to produce urn powders was once not possiblebecause of emulsion into Urn particles. Our most important finding is that such emulsion canbe avoided. We prepare Y2O3-doped ZrO2 nano-crystalline powder by Sol synthesis withzirconyl chloride as precursor in aqueous solution. The prepared powders have a narrow sizedistribution and a low agglomerate strength of 46 MPa. Preliminary studies indicate that thepowder size is dependent on the concentration of the precursor compound. By regulating theconcentration, powders of tens of to several urn in diameter can be prepared. The minimuncrystallite size of the powders is 6 nm, which is determined by the critical particle size of thesol.