Abstract
Unusual polydispersive dielectric response of undiluted Cd2Nb2O7 pyrochlore between 100 Hz to 6 MHz and 77 to 300 K is reported. Below TC ≈ 198 K, the relaxation typical of (i) a normal ferroelectric (FE), (ii) a relaxor FE with glassy behaviour, and (iii) a dipolar glass develop in the system. Based on a weak bonding between the pyrochlore-structure-forming (NbO6)n− and (CdO8)n− networks, a mechanism is proposed that explains an occurrence of the orientational dipolar disorder and disordered states of different nature with decreasing temperature.
Acknowledgement
The financial support from KBN (Poland), Project 2P03B04722 is acknowledged.