溶胶-微乳液-凝胶法合成堇青石陶瓷纳米粉体

Sol-emulsion-gel Synthesis of Cordierite Ceramic Nanopowder

配制以A l(NO3)3.9H2O、Mg(NO3)2.6H2O和TEOS为前驱体原料的溶胶,使其增溶于Triton X-100/正己醇/环己烷反相微乳液体系中,合成了堇青石纳米粉体。对微乳液拟三元相图、凝胶所需pH值及温度条件、溶胶凝胶机理及析晶过程进行了研究。结果表明,该方法合成纳米堇青石的最佳pH值为5.5,微乳液体系的最佳增溶温度为45℃。所得纳米粉体能在950℃下低温致密化烧结,具有良好的介电性能(ε<3,tanδ<0.001;1 GHz),是应用于高频片式电感等电子元器件的理想介质材料。

The sol was prepared using Al（NO3） 3·9H2O,Mg（NO3）2·6H2O and TEOS as the precursor,then it was solubilized in reverse micro-emulsion system including Triton X-100/n-hexanol/cyclohexane,and the cordierite nano-particles were synthesized ultimately.The pseudo ternary phase diagram,pH value and temperature conditions required for the sol-emulsion-gel,gel mechanism and the crystallization process were studied.The results showed that the best suitable pH value was 5.5 and the optimum solubilization temperature of micro-emulsion was 45 ℃.The cordierite nanopowder could be sintered compactly at 950 ℃ with excellent dielectric properties（ε〈3,tanδ〈0.001;1 GHz）,it was an ideal dielectric material used at high frequency chip inductors and other electronic components.