Investigation of Ferroelectric Layered Perovskite Barium Bismuth Tantalate Prepared by Solid-State Reaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Barium bismuth tantalate-BaBiTa2O9 has been prepared by conventional method based on solid-state reaction using BaCO3, Bi2O3 and Ta2O5 as starting materials. It was added excess of 10 mol% of bismuth aiming to improve the dielectric and ferroelectric properties. The calcinated powders and sintered pellets were analyzed by XRD and SEM. BaBiTa2O9 ceramics with high density was obtained at sintering temperature of 1050 degrees C for 2 h. The faced grains with a rod-like morphology were observed for BaBiTa2O9 with 10 mol% excess bismuth. The dielectric constant measured at frequency of 100 kHz at room temperature was 389 with dielectric loss of 0.032. BBT ceramic prepared with excess of 10 mol% bismuth possesses ferroelectric properties with remnant polarization of P-r approximate to 15 mu C cm(-2) and coercive field of E-c approximate to 58 kV cm(-1). The hysteresis loop is very well performed with the shape characteristic of ferroelectric materials.