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Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Bigham,Jerry Marshal; Paesano Junior,Andrea; Berndt,Graciele; Inoue,Tadeu Takeyoshi; Nonaka,Adriele Galeti. |
Synthetic aluminum-substituted maghemites were characterized by total chemical analysis, powder X-ray diffraction (XRD), Mössbauer spectroscopy (ME), and vibrating sample magnetometry (VSM). The aim was to determine the structural, magnetic, and hyperfine properties of γ-Fe2-xAl xO3 as the Al concentration is varied. The XRD results of the synthetic products were indexed exclusively as maghemite. Increasing Al for Fe substitution decreased the mean crystalline dimension and shifted all diffraction peaks to higher º2θ angles. The a0 dimension of the cubic unit cell decreased with increasing Al according to the equation a o = 0.8385 - 3.63 x 10-5 Al (R²= 0.94). Most Mössbauer spectra were composed of one sextet, but at the highest substitution rate of 142.5... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Isomorphous substitution; Hyperfine parameters; Spinel; Ferromagnetic. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600013 |
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