Dielectric behaviors of Nb2O5-Co2O3 doped BaTiO3-Bi(Mg1/2Ti1/2)O3 ceramics
Nb2O5 and Nb-Co doped 0.85BaTiO 3-0. 15Bi(Mg 1/2Ti 1/2)O 3 (0.85BT-0.15BMT) ceramics were investigated. From XRD patterns, undesired phase was observed when the (Nb 2O 5/Nb-Co) doping levels exceed 3 wt.%/2 wt.%, giving rise to the deteriorate dielectric constant. The 0.85BT-0.15BMT ceramics doped with 2 wt.%Nb 2O 5 was found to possess a moderate dielectric constant (ε ∼ 1000) and low dielectric loss (tan δ = 0.9%) at room temperature and 1 kHz, showing flat dielectric behavior over the temperature range from -55 to 155°C. It was found that the formation of core-shell structure in the BT based ceramics is controlled by the doping sequence of Nb- and Bi-oxides. 2011 Elsevier Ltd and Techna Group S.r.l.