Caracterização e estudo de propriedades elétricas do SrBi4Ti4O15 (SBTi) dopado com PbO2

Abstract

SrBi4Ti4O15 (SBTi) ceramic, a perovskite with cation deficient system as in A5BB4O15 was prepared by high-temperature solid-state reaction method using high purity ingredients (carbonates and oxides): Oxide of Bismuth (Bi2O4), Oxide of Titan (Ti2O4), and Strontium Carbonate (SrCO3), in required stoichiometry. The previous powders were mixed and ball-milled thoroughly in an agate mortar for 2h and calcined in air atmosphere at 850oC for 3h. The mixing and calcinations were repeated several times. Then the calcination was finally completed. The compounds were checked by X-ray diffraction (XRD) techniques. SBTi was doped, in following proportions: 2%, 5%, 10% and 15% of PbO2 mass and sintered as pellets that were made under a uniaxial pressure using a press and in powder at 950C for 3h. Polyvinyl alcohol (PVA) was used as a binder to reduce the brittleness of the pellets. Finally, the studies of electric and dielectric properties were accomplished by using these pellets.