Estudo das propriedades diéletricas do SrBi4Ti4O15 (SBTi) dopado com PbO

Abstract

The ceramic SrBi4Ti4O15 (SBTI), cation-deficient perovskite A5B4O15, was prepared by the method of solid state reaction and then doped with PbO (in the range 2-10% by weight). The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance spectroscopy at room temperature. The X-ray analysis was performed by the Rietveld refinement. The micrographs of the samples show globular-shaped grains (doped PbO). The dielectric properties: dielectric constant (K' or ') and dielectric loss tangent (tan ), were measured at room temperature in the frequency range 100 Hz - 1 MHz dielectric properties of these 1 MHz sample doped with 10 % PbO showed the dielectric constant K´ = 168.34 and dielectric loss tangent tan = 7,1.10-2. These results show a good possibility of miniaturization of electronic devices such as capacitors.