Análise estrutural e morfológica de ferrita NiFe2O4 dopada com cromo

• Autor(a) principal: Costa, Ana Cristina Figueiredo M.
• Data de Publicação: 2011
• Outros Autores: K.M.S.Viana, Miola, Eduardo José, Antonio, Selma Gutierrez, Santos, Carlos de Oliveira Paiva [UNESP], Kiminami, Ruth H. G. A.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://cct.ufcg.edu.br/revista/index.php/REMAP/article/view/192; http://hdl.handle.net/11449/123489
• topic: Ferrita de níquel; reação de combustão; partículas nanométricas; Nickel ferrite; combustion reaction; particle nanosized

This paper reports on the effect of the substitution of Fe3+ for Cr3+ ions in the spinel lattice of the powders was investigated. Nickel ferrite powders with a NiFe2-xCrxO4 nominal composition (x = 0.0; 0.5; 1.0 and 1.5 mol of the chromium) were synthesized by combustion reaction using urea as fuel. The powders resulting were characterized by XRD, nitrogen adsorption by BET, SEM and Mössbauer spectroscopy (57Fe Mössbauer spectra). The results show that the substitution of the Fe3+ for Cr3+ions increased the crystalline degree of the phase, reduced the superficial area and consequently increased the particle size. The Mössbauer spectra of the samples also confirm the distribution of the particles size by the magnetic properties. Analyze of the spectra Mössbauer gives an estimate of the superparamagnetic and ferromagnetic particles behavior in each sample for several chromium concentrations.