Dielectric loss anomalies of 0.68PMN-0.32PT single crystal and ceramics at cryogenic temperature

The temperature dependence of dielectric constant and loss were investigated for poled and unpoled [001]-oriented 0.68PMN-0.32PT single crystal and ceramics at cryogenic temperature. Two abnormal loss peaks, which are frequency dependent, are presented for all the samples. One of abnormal loss peaks locates in the range from 50 to 80 K and the other was observed in the range from 200 to 300 K. The difference of the abnormal loss between the single crystal and ceramics were compared. It is assumed that the dielectric loss anomalies at cryogenic temperature are related to the change of domain structure and phase structure parameter induced by temperature.