MICROESTRUTURA, PROPRIEDADES MAGNÉTICAS E DIELETRICAS DA FERRITA DE COBRE E NIÓBIO.

To obtain a copper and niobium ferrite with the structure of spinel samples were produced by solid state reaction process stoichiometry NbxCu1-xFe2O4 (x = 0.0, 0.10 and 0.20) and sintered at 1000°C for 8 h and subsequent characterization of its microstructure and determine their magnetic properties. The structural characterizations, microstructural and magnetic were performed using the techniques of X-ray diffraction, scanning electron microscopy (SEM), vibrating sample magnetometer of and magnetic thermal analysis. The results showed that the sample with x = 0.00 was formed by the phase cubic and tetragonal spinel structure. The stoichiometry samples with x = 0.10 and 0.20 were formed exclusively by the phase cubic spinel structure and Nb2FeO6 phase with orthorhombic structure. The hysteresis curves showed soft magnetic material characteristics and its saturation magnetization increased with the concentration of niobium. As electrical permissivity measurements and impedance characterization of the samples, the range of 1 Hz to 10 MHz, suggest that the electrical characteristics of the samples suffer greater influence of the grain boundary. [ABSTRACT FROM AUTHOR]