CaCu_3Ti_4O_(12)的制备及电导研究

Study of Preparation and Conductivity of CaCu_3Ti_4O_(12)

按CaCu3Ti4O12的组分进行化学配比,经850℃-955℃预烧、900℃-1100℃烧结6 h,成功制备了CaCu3Ti4O12粉体前驱体和CaCu3Ti4O12巨介电常数陶瓷材料.用X射线衍射仪、扫描电镜(SEM)对体系进行了结晶性能和形貌观察.用阻抗分析仪在25 K-355 K温区范围内测定了陶瓷样品的介电性能和电导.结果表明:955℃预烧的粉体在1060℃温度下只需烧结6 h,陶瓷样品的介电值在10 kHz频率下,在100 K-355 K范围内可高达2.0×105,与文献报道的相比,其介电性能最好且烧结时间最短;电导与温度及频率的关系是由电子、声子与外场的共同作用决定的.

According to the proportion of CaCO3, CuO and TiO in CaCu3Ti4O12, CaCu3Ti4O12 powder precursors and CaCu3Ti4O12 ceramics with giant dielectric constants are successfully prepared by sintering at 900 ℃-1100 ℃ for 6 hours using the powder prepared at 850 ℃ -955 ℃. The phase structure and the morphology of CaCu3Ti4O12 are observed by X-ray diffraction.and scanning electron microscopy respectively. Besides, the dielectric constant and conductivity of CaCu3Ti4O12 are measured by an inductance-capacitance-resistance（ICR） at 25 K-355 K. The results show that the ceramics, with a higher dielectric constant of 2.0×10^5 at the frequency of 10 kHz and the extent of 100 K-355 K, are prepared by sintering at 1060℃ only for 6 hours using the powder prepared by sintering at 955 ℃. Compared with the report in existing literature, its dielectric properties are the best and sintering time is the shortest. Furthermore, the relationship among the conductivity, frequency and temperature depends on the interaction of electrons, phonons and external field.