Investigations of the divalent metal ions Zn2+, Co2+, Ni2+ doped ultra-wide temperature stable BBNN system

Multi-component BaTiO3-Bi0.5Na0.5TiO3-Nb2O5 (BBNN) system doped with divalent metal ions (Zn2+, Co2+, Ni2+) was prepared by the conventional solid-state method.The X-ray diffraction patterns revealed all samples exhibited perovskite (P4mm) single phase. The dielectric properties and micro-mechanisms were discussed and validated. Novel theories, based on the characteristics of the different kinds of dielectric polarization, are proposed to explain the dielectric anomalies in the dielectric system. The relationships between microstructure and the dielectric properties were investigated systematically for the first time. The samples doped with 15 mol% Zn2+/Co2+ presented good dielectric properties of an ultra broad temperature stable range (from -50 and >300), high dielectric constant (epsilon similar to 1925 for Zn-2/epsilon similar to 1341 for Co2+) and low dielectric loss (tan delta < 0.02) were obtained. These features made the ceramics system have high practical values for miniaturization and harsh environments applications. (C) 2016 Published by Elsevier Ltd.