Structural and magnetic influence of yttrium-for-iron substitution in cobalt ferrite

I. HAÏK DUNN; S. E. JACOBO; P. G. BERCOFF

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2017 vol. 691 p. 130 - 137

0925-8388

Yttrium-substituted cobalt ferrites of nominal composition CoYxFe1.98-xO4,x=0; 0.1; 0.2; 0.3, were prepared using the sol-gel combustion method. A slightiron deficiency in the formulation was designed in order to improve yttriumsolubility in the spinel structure. The inclusion of Y in the lattice reached10% cationic substitution. XRD Rietveld analysis and Raman spectra confirm thatyttrium enters the lattice in octahedral sites, increasing the inversionparameter of cobalt ferrite. Mössbauer results confirm the cation distributionobtained with Rietveld refinements. Saturation magnetization and Curietemperature decrease with iron substitution, confirming the B site occupancy ofY ions. Yttrium inclusion promotes a cation distribution which modifies theRaman spectra. A model is proposed to explain the observed vibrational modes.