关键词: 镧掺杂, 钛酸钡, 粉体, 陶瓷, 金属有机盐, 前驱物, 包覆

Abstract:

In order to satisfy the need for thin layer of dielectric ceramics with small-size grains and high dielectric constant in MLCCs applications,the surface-coating technique was utilized to modify hydrothermal-synthesized BaTiO₃(BT)with La-organic compound as the precursor,which was coated on the powders uniformly.It is found from experiments that the organic component completely decomposes at 650 ℃ and a single-phase solid solution
(Ba_(1-x) La_2x/3 )TiO₃ forms after sintering.It is also found that,with the increase in La content,the peak of tempera-ture-dependence of dielectric constant of La-doped Si-BT ceramics is compressed and moves to a low-temperature region,that the average Curie temperature t_av decreases linearly with La content, and that the grain size and dielec-tric properties of the ceramics are greatly influenced by the increasing rate of sintering temperature.

Key words: lanthanum doping, barium titanate, powder, ceramic, metal-organic compound, precursor, coating