Abstract
The dielectric properties and structural behavior of perovskite-related CaCu3Ti4O12 were studied at high temperatures. The dielectric constant increases gradually with increasing temperature and shows a shoulder-like round anomaly at approximately 630 K at 10 kHz. At 732 K, a new dielectric anomaly was found, where the peak value of the dielectric constant, εpeak≃2.8×106 at a frequency of 10 kHz. The lattice constant and X-ray intensity of the (880) reflection also exhibit an anomaly at 732 K. These findings indicate that CaCu3Ti4O12 undergoes a structural phase transition at 732 K.