Sinterização via energia de microondas de nanoferritas Ni-Zn para desenvolvimento de dispositivos magnéticos moles.

Abstract

This work aims to prepare nanostructures of Ni-Zn ferrites sintered using the energy of microwave oven. These materials will have their performance evaluated for use in soft magnetic devices for high frequency to minimize losses in generation, distribution and use of electricity. The powders were prepared according to the concept of the chemistry of propellants and explosives using a vitreous silica crucible and glycine as fuel for the synthesis and subsequently pressed in the form of chips and then sintered in a microwave oven at a temperature of 1200oC/2h. The results show that the sample synthesized at lower power with exposure time of 10 minutes allowed the formation of samples after sintering at the geometrical density and bulk density, leading to a reduction in apparent porosity. The results of XRD show the formation of Ni-Zn ferrite phase as major phase and traces of secondary phase hematite. All sintered samples showed relatively large grains formed, but with high inter-and intragranular porosity. Through the curves of hysteresis is observed that the samples showed curves with hysteresis characteristic of soft magnetic material.