Síntese por reação de combustão e caracterização de ferrita Ni-Zn dopada com íons Cu2+ e Al3+.

Abstract

The magnetic ferrites are ceramic materials, characterized by containing Fe203 as main component and exhibit spontaneous magnetization in the absence of applied magnetic field. The ferrites have achieved great industrial importance which may be used in a wide range of applications ranging from the huge demand for the manufacturing of electrical and electronic devices like magnetic soft and hard, until, as shippers applications of drugs, electromagnetic radiation absorber between others. This study aims to investigate the effect of doping of 0,3 mol of Al3+ and 0,1 mol of Cu2+ on the structure, morphology and magnetic characteristics of Ni-Zn ferrite synthesized by combustion reaction using a stainless steel container and as a source of resistance heating spiral. The samples were characterized by X-ray diffraction (XRD), chemical analysis by X-ray fluorescence, energy dispersive (EDX), infrared spectroscopy (FITR), scanning electron microscopy (SEM), N2 adsorption, and measures magnetic. The results showed the formation of inverse spinel phase of Ni-Zn ferrite for samples as synthesized, after calcination. For the composition doped with 0,1 mol of Cu was observed traces of the second phase of ZnO. The FTIR spectra of the samples show two absorption bands characteristic of OH group stretching band corresponding to stretching and NO resulting from nitrate. The synthesized samples showed a high amount of surface area, therefore nano-particle size. The morphology of ferrite samples doped with and without calcination resulted in the appearance of irregular clumps and not dense. The EDS mapping showed a good chemical homogeneity of constituent elements characteristic of Ni-Zn ferrite with both dopants. The total mass loss by TGA and DTA results was lower for the systems doped and annealed with 0,3 mol of Al3+ and 0,1 mol of Cu2+. The Ni-Zn ferrite doped with 0,3 mol of Al3+ and 0,1 mol of Cu2+ showed superparamagnetic behavior and after calcination, showed the formation of a material with soft magnetic behavior (magnetization and demagnetization easy). The calcined samples are promising soft magnetic devices and absorbers of electromagnetic radiation, and the non-calcined for other applications such as catalysis, sensors and drug carriers.