The effect of post-sintering annealing upon the dielectric properties of CaCu3Ti4O12 was investigated at 200 to 400K. A dielectric peak, featuring thermally activated Debye-like behavior, was observed at around 340K and 100Hz. This peak could be eliminated by annealing in an oxidizing atmosphere, and created by annealing in a reducing atmosphere. The peak was explained in terms of the combined contributions of n- and p-type carriers.

Oxygen-Vacancy-Related Dielectric Anomaly in CaCu3Ti4O12 - Post-Sintering Annealing Studies. C.C.Wang, L.W.Zhang: Physical Review B, 2006, 74[2], 024106 (4pp)