Sinterização de ferritas Ni-Zn em micro-ondas: avaliação da temperatura e tempo de exposição.

Abstract

The study of the processing of Ni-Zn ferrite is of utmost importance for improving their magnetic properties, since they are directly influenced by the final microstructure of the material and get a ferrite with a uniform microstructure is a major challenge in the advancement of new technologies. This study aims to evaluate the influence of temperature and exposure time on stage sintering of Ni-Zn ferrite by microwave energy, and their subsequent structural characterization, microstructural, physical and magnetic order to obtain materials with soft magnetic behavior. The samples of Ni-Zn ferrite were sintered using microwave energy at temperatures of 900°C, 1000°C, 1100°C and 1200°C and exposure time of 10, 20 and 30 minutes, respectively. Then were characterized by density measurements, X-ray diffraction (XRD), fluorescence spectroscopy X-ray energy dispersive (EDX), scanning electron microscopy (SEM) and magnetic measurements. Through the analysis results showed that the effect of varying the exposure time was the predominant sintering temperature variation in the measured density values, a maximum density value of 96% for the sintered sample at higher temperature and longer exposure time. All samples obtained from the training phase Nid^/.no^Fc/)^ with all peaks with high intensity and high basal width for all sintering conditions. The variation of both the time and the sintering temperature is not significantly modify the chemical composition of the sintered ferrite, in general experimental values were close to theoretical values calculated. It was possible to obtain a nanostructure with behavior characteristic of a soft magnetic material, with maximum saturation magnetization of 71 emu / g for the sample sintered at higher temperature and longer time of exposure.