Síntese por reação de combustão em escala piloto de nanoferritas Mn1-XZnXFe2O4 para uso como materiais absorvedores de radiação eletromagnética.

Abstract

Mn-Zn ferrites are ferrimagnetic materials used in the technological area due to their excellent electromagnetic properties, and can be applied in various sectors, such as materials that absorb electromagnetic radiation. Based on this application, the objective of this research was to develop, through the combustion reaction synthesis method, nanoferrites of the Mn1-xZnxFe2O4 system (where x = 0.0, 0.35, 0.5, 0.65 mol of Zn) on a pilot scale with 200g / reaction batch and its subsequent incorporation in silicone rubber, in order to present suitable nanocaracteristics to be used as electromagnetic radiation absorbing materials in different frequency bands, which allows its use in different sectors Aerospace. The samples were characterized by Xray diffraction, X-ray fluorescence by dispersive energy, Infrared spectroscopy with Fourier transform, Granulometric distribution, Scanning and Transmission Electron Microscopy, Atomic Force Microscopy, Nitrogen Adsorption Textural Analysis, Magnetic and Electromagnetic Measurements. It was observed that the synthesis by combustion reaction was a favorable technique to obtain the monophasic Mn1- xZnxFe2O4 (x = 0; 0.35, 0.5; 0.65) on a large scale of production. Morphologically the addition of Zn to the MnFe2O4 system caused a slight reduction in the size of the agglomerates and reduction in the particle size, however this behavior was not linear. All samples showed a magnetic behavior characteristic of soft magnetic materials, with maximum saturation magnetization of 62 emu/g. The nanoferrites, regardless of the composition used, were incorporated with good uniformity within the silicon matrix, which provided the maximum saturation magnetization value of 24 emu/g. Regarding the electromagnetic responses, it was observed that the ferrite load presented values of maximum absorption of -30 dB in the 8 GHz range, and when incorporated in the silicone maximum absorption values of -24 dB in the 6 GHz range, demonstrating that the obtained products presented promising characteristics for the application as Materials absorbers of electromagnetic radiation.