Infrared and Mossbauer investigations of CdGaxFe2-xO4 spinels

The Cd-Ga ferrite system CdGaxFe2-xO4 (where x = 0, 0.6 and 1.0) was studie d by means of infrared (IR) and Mossbauer spectroscopy. IR spectra revealed two prominent bands nu (1) and nu (2) which were assigned to tetrahedral a nd octahedral metal complexes, respectively. The position of the highest fr equency band nu (1) showed an increase with increasing gallium concentratio n. The lowest band nu (2) was broadened and diffused with gallium substitut ion. Mossbauer spectra at room temperature exhibited paramagnetic doublet l ines. As a result of distortion in the oxygen positions surrounding the B-s ites, the quadrupole interaction in the Mossbauer spectra increased with in creasing gallium concentration. IR and Mossbauer spectra revealed the absen ce of Fe2+ ions at both tetrahedral and octahedral sites.