Magnetic properties of Cr3+ substituted BaFe12O19 powders grown by a sol-gel method

Cr3+ substituted Ba-hexaferrite was fabricated by a sol-gel method. The cry stallographic and magnetic properties of BaFe12-xCrxO19 (0 less than or equ al to x less than or equal to 17) were investigated XRD, Rutherford backsca ttering spectrometry, vibrating sample magnetometry and Mossbauer spectrosc opy. The crystal structure was found to he magnetoplumbite, typical of M-ty pe hexagonal ferrite. By substituting Fe3+ in BaFe12O19 by Cr3+ we have bee n able to attribute the Mossbauer parameters to the 5 crystallographic site s of the structure, Only the octahedral sublattices were occupied by Cr ion s. The isomer shifts indicate that the valence state of the Fe ions was Fe3 +. The Curie temperatures of BaFe12-xCrxO19 decreased linearly incrasing Cr -substitution, at a rate of 55 K/Cr atom.