Estudo das propriedades dielétricas em microondas da cerâmica BNO (BiNbO 4 ) com adição de ZnO

The objective of this work is to study the microwave dielectric properties of the compound BiNbO4 (BNO) with addition of ZnO and discuss the influence of the additions in view of possible applications in dielectric resonators. The BNO ceramic has been produced by the standard method of solid state. The ZnO (3, 5 and 10% by weight) was added in order to analyze the changes in the dielectric properties of ceramic bulks produced. Polyvinyl alcohol (PVA) was also incorporated into the manufacturing process as organic binder. The samples were characterized by X-ray diffraction (XRD) and a study of dielectric properties using the technique of Hakki Coleman was done. The Rietveld refinement indicated that the pure BNO produced, has an orthorhombic type structure (space group: P nna 52). The dielectric properties: dielectric constant ( ε ’), dielectric loss factor (tg δ ) and quality factor (Qu), were measured ambient temperature. The presence of ZnO more melting PVA binder in all concentrations change the dielectric properties of the samples compared to the standard sample (BNO pure).