Ti deficiency effect on the dielectric response of CaCu 3Ti 4O 12 ceramics

• Published in: Solid state communications Vol. 141; no. 8; pp. 440 - 444
• Main Authors: Chen, K., Liu, Y.F., Gao, F., Du, Z.L., Liu, J.M., Ying, X.N., Lu, X.M., Zhu, J.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2007
• Subjects: D. Correlation; D. Relaxation; D. Ti deficiency; D. Correlation; 77.22.Gm; D. Relaxation; 77.84.Dy; D. Ti deficiency
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2006.12.004

Single phase ceramics CaCu 3Ti 4.0O 12 and CaCu 3Ti 3.9O 12 have been prepared using the traditional solid-state reaction method. Compared with the stoichiometric ceramics CaCu 3Ti 4.0O 12, Ti-deficient ceramics CaCu 3Ti 3.9O 12 have the larger lattice parameter, the higher force constant, and smaller dielectric constant and the lower dissipation factor, although their fundamental characters of dielectric response are similar. Their characteristic relaxation frequencies are not well fitted with the Arrhenius Law but a tentatively supposed relation. With the Cole–Cole Law, the fitted broadened factors of dissipation peaks are 0.5433 and 0.8651 for CaCu 3Ti 3.9O 12 and CaCu 3Ti 4.0O 12, respectively. All facts mentioned above imply that mutually correlated motion of Ti ions or defects may be expected to be responsible for the giant dielectric constant and high dissipation factor of CaCu 3Ti 4.0O 12.