Mossbauer, infrared, and X-ray studies of Ti-doped CoCr1.2Fe0.8O4 ferrites

The spinel samples Co1+xTixCr1.2-2xFe0.8O4 (0 less than or equal to x less than or equal to 0.6) were investigated at room temperature using Mossbauer, X-ray, and IR spectra. The Mossbauer spectra for x less than or equal to 0.1 showed only broad six-lines patterns and for 0.2 less than or equal to x less than or equal to 0.5 showed, in addition to the broad six-lines patterns, a central paramagnetic phase C. The spectrum for x = 0.6 showed only paramagnetic phase C. The six-lines patterns were analysed to two magnetic patterns attributed to Fe3+ ions on the tetrahedral A-sites and to Fe2+ and Fe3+ ions on the octahedral B-sites. The broader B-site pattern appeared to be composite for x less than or equal to 0.3, thus it has been analysed to its multicomponents. The paramagnetic phase C was analysed to two quadrupole doublets due to Fe3+ ions at the A- and B-sites. The obtained hyperfine interaction parameters have been studied and discussed as functions of the composition factor x. The cation distributions have been estimated and supported by Xray studies. Six absorption bands were observed in the IR spectra and attributed to Fe3+ ions on the A- and B-sites, to Fe2+ and Co2+ ions, and to the energy of the sublattices. The IR bands revealed the existence of Fe2+, ions in the samples. The true and theoretical lattice parameters, the oxygen positional parameter, and the ionic radii, bonds, and edges of the A- and B-sites have been determined from the X-ray analysis. They were studied and discussed in dependence of x.