溶胶-凝胶法制备CaCu_3Ti_4O_(12)陶瓷及其介电性能研究

Preparation and Dielectric Properties of CaCu_3Ti_4O_(12) Ceramics by Sol-gel Method

通过溶胶-凝胶法制备Ca Cu3Ti4O12（CCTO）粉体,经成型、烧结制成陶瓷,研究了烧结温度和保温时间对陶瓷显微结构和介电性能的影响。结果表明,在10501120℃下,随着烧结温度升高,陶瓷晶粒长大,致密度先增大后减小,经1100℃烧结所得陶瓷晶界清晰,晶粒较大且生长均匀;在1100℃下,随着保温时间的延长,陶瓷晶粒尺寸和致密度先增大后减小,经保温15 h烧结所得陶瓷具有最大的晶粒和致密度,其在1 k Hz下的相对介电常数为1.77×104。

Ca Cu_3Ti_4O_(12) powders were synthesized by the sol-gel process,and the ceramic was obtained by dry pressing and sintering using the powder. The effect of sintering temperature and holding time on microstructure and dielectric properties was studied. The results show that the grain size grow larger,and that the density of ceramic firstly increases and then decreases with increasing sintering temperature from1050 ℃ to 1120 ℃. The ceramic obtained by sintering at 1100 ℃ show a relatively homogeneous microstructure with clear grain boundaries and low porosity. As the holding time increasing,the grain size and density of CCTO samples firstly increase and then decrease. The ceramic samples obtained by sintering at 1100 ℃ for 15 h show highest density and largest grain size,and the dielectric constant is 1.77 × 104 at 1 k Hz.