XRD, dielectric and magnetic studies of Cd2Nb2O7 ceramics obtained from mechano-synthesized nanopowders

摘要

Dielectric response, thermal and magnetic properties of hot-pressed ceramics obtained from Cd2Nb2O7 nanopowders synthesized by high-energy milling of CdO and Nb2O5 were studied. The transition from cubic to orthorhombic phase was found to be shifted downwards by ∼50 K in comparison with that reported for single crystals. Below 150 K four relaxation processes were revealed and characterized. A broad specific heat anomaly with maximum at 18K, similar to that reported for single crystals was observed. Small magnetic hysteresis loop observed for the ceramics at 4 K can be due to defects introduced in the process of mechanical synthesis.