钛酸铜镧粉末及陶瓷的制备、结构及介电性能研究

采用溶胶-凝胶法制备La2/3Cu3Ti4O12(LCTO)粉末和陶瓷,详细研究了溶胶条件对LCTO粉末和陶瓷的显微结构的影响.结果表明溶胶条件在Ti4+浓度为1.0 mol/L,pH=0.3,[H2O]/[Ti4+]=5.6的条件下制备LCTO的粉末分散程度较好,颗粒均匀.当在1100 ℃下烧结保温10 h后制备的LCTO陶瓷显示出较大的晶粒尺寸、高的致密度以及高的晶界电阻(1.95×105Ω· cm).另外,在保持高达(0.92~1.6)×104的巨介电常数同时,介电损耗降低至0.041.模拟计算LCTO陶瓷的晶界电导激活能为0.664 eV和0.893 eV.

Preparation,Microstructure and Dielectric Performance of La2/3Cu3Ti4O12Powders and Ceramics

The La2/3Cu3Ti4O12(LCTO)ceramics and powders were prepared by the sol-gel method.Effect of sol conditions on microstructure of LCTO powders or ceramics were investigated systematically.The experimental results showed that LCTO powder prepared at the concentration, pH value and the molar ratio of the water and titanium of the sol for 1 mol/L, 0.3 and 5.6 showed more dispersion and homogeneity.After sintered at 1100 ℃for 10 h,the LCTO ceramics exhibited larger grain size, higher density and higher grain boundary resistance(1.95×105Ω· cm),much higher dielectric constant(0. 92-1.60×104)and lower dielectric loss(0.041).The conduction activation energy was calculated to be about 0.664 eV and 0.893 eV.