Abstract： Cubic perovskite-related ceramic CaCu3Ti4O12 has a very high dielectric constant larger than 10000 in the kilohertz frequency region. It is almost constant in the 100--600K region. The ceramic compounds were prepared by conventional solid-state reaction at different sintering temperatures 1040°C(C04),1060°C(C06), 1080°C(C08), and 1100°C(C10). Impedance spectroscopy on CaCusTi4O12 ceramics demonstrates that they are electrically heterogeneous and consist of semi-conducting grains with insulating grain boundaries. It is shown that C06 is the most suitable one for device applications. Surface observation and analysis of the grain-boundary-grained structure were carried out by using scanning electron microscopy, which confirms that the samples have clearly different crystal grain sizes and C06 has a larger grain size of about 20μm. Compared to the dielectric relaxation spectroscopy, the mechanical relaxation spectroscopy on C06 was performed and a mechanical loss peak was found, which was attributed to the thermally activated behaviour being immanent in the grains.
(Anelasticity, internal friction, stress relaxation, and mechanical resonances)
引用本文:
CHEN Kai;LI Wei;LIU Yun-Fei;BAO Peng;LU Xiao-Mei;ZHU Jin-Song. Investigation of the Size Effect on the Giant Dielectric Constant of CaCu3Ti4O12 Ceramic[J]. 中国物理快报, 2004, 21(9): 1815-1818.
CHEN Kai, LI Wei, LIU Yun-Fei, BAO Peng, LU Xiao-Mei, ZHU Jin-Song. Investigation of the Size Effect on the Giant Dielectric Constant of CaCu3Ti4O12 Ceramic. Chin. Phys. Lett., 2004, 21(9): 1815-1818.
2004, Vol. 21 
