Structure, microstructure and dielectric properties of 100-x(Bi0.5Na0.5)TiO3-x[SrTiO3] composites ceramics

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)

Processo FAPESP: 09/50303-4

In this paper, lead-free 100-x(Bi0.5Na0.5)TiO3-x[SrTiO3] composites ceramics with (0a parts per thousand currency signxa parts per thousand currency sign9) were synthesized by the solid-state reaction method. Their structure, dielectric, ferroelectric and piezoelectric properties were investigated. X-ray diffraction patterns, Rietveld refinement data and Raman spectra revealed that the SrTiO3 cubic structure was completely diffused into the (Bi0.5Na0.5)TiO3 lattice with rhombohedral structure. The scanning electron microscopy images showed change in grain morphology from rectangular-like to quasi-spherical grain with increase in SrTiO3 content. The dielectric permittivity increases, the Curie temperature decreases and the peaks become broaden with raise of SrTiO3 content. Ferroelectric and piezoelectric properties of these composites ceramics showed degenerated behavior with increase of SrTiO3.