溶胶-凝胶法制备Na_(1/2)La_(1/2)Cu_3Ti_4O_(12)粉体及陶瓷的结构与巨介电性研究

Microstructure and High Dielectric Performance of Na_(1/2)La_(1/2)Cu_3Ti_4O_(12) Powder and Ceramics by Sol-gel Method

采用溶胶-凝胶法制备Na_(1/2)La_(1/2)Cu_3Ti_4O_(12)(NLCTO)粉体和陶瓷样品,探讨不同Ti^(4+)浓度、pH值和水含量对NLCTO粉体和陶瓷结构的影响。结果表明在Ti^(4+)浓度为0.75~1.0mol/L,pH=0.3~1.3,[H_2O]/[Ti^(4+)]=11∶1的条件下制备的干凝胶在800℃预烧后,粉体分散程度较好,颗粒均匀。在获得优越NLCTO粉体基础上制备的陶瓷材料介电常数约可达到1.9×10~4以上,介电损耗降低到0.039。

Na1/2La1/2Cu3Ti4O12 powder and ceramics were successfully achieved by sol-gel method. Effect of concentration,p H value and the molar ratio of the water and titanium of the sol on microstructure of NLCTO powder and ceramics were investigated in detail, respectively. The results found that the concentration,p H value and the molar ratio of the water and titanium of the sol for 0. 75-1. 0 mol/L,0.3-1. 3 and 11. 0,respectively,after calcining at 800 ℃ for 10 h,NLCTO powder show more dispersion and homogeneity. Based on the superior NLCTO powder,dielectric constant of the prepared NLCTO ceramics increased to 1. 9 × 10^4,and dielectric loss decreased to 0. 039.