paper 150304201337

Abstract

BiNbO4 ceramics were prepared by the solid state reaction, and the as-prepared samples were treated at temperatures between 600 and 1200◦ C. The samples structure was ana- lyzed by X-Ray Diffraction and the morphology was studied using Scanning Electron Microscopy. The low-perturbation resonant cavity method was used to calculate the dielectric properties of the ceramic material. The samples heat treated at temperatures above 800◦ C present the BiNbO4 crystal phase, being the predominant phase on the samples treated above 950◦ C. The samples treated below 900◦ C present the Bi5 Nb3 O15 secondary phase, which seems to be responsible for the highest dielectric constant values observed at room temperature. The dielectric losses of all samples are always lower than 10−4 . The electromagnetic fields, inside the cavity, without and with the cylindrical sample were simulated using the COMSOL Multiphysics software.

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Luis Cadillon Costa

C. S. Ferreira

M. P. F. Graca

T. Santos