Structural and infra-red studies of Ni1+xPbxFe2-2xO4 system

The structural properties and IR absorption spectra of Pb4+ substituted Nickel ferrites having general formula Ni1-xPbxFe2-2xO4 (where x=0.0, 0.1, 0.2, 0.3, 0.4 and,0.5) were investigated. Samples of Ni-Pb-Fe system were prepared by the ceramic technique. The X-ray analysis confirmed the single-phase formation of the samples. The lattice parameter was found to increase linearly with composition (x), which is attributed to ionic size difference of cations involved. The X-ray density was also found to increase linearly with composition.(x). X-ray intensity ratio calculations show that Ph4+ occupies A and B sites, which replace Fe3+ ions and added Ni2+ ions substitute for B site iron ions. The IR spectra of Ni-Pb ferrite system have been analyzed in the frequency range 200-800 cm(-1). The IR bands show shift towards the lower frequency side with the addition of Ph4+ for x=0.0-0.2, which can be attributed to increase in lattice parameter. The bond lengths R-A and R-B were found to increase with composition (x). (C) 2002 Elsevier Science B.V. All rights reserved.