FAR-INFRARED SPECTRA OF LITHIUM TITANIUM MIXED FERRITES

The far-infrared spectra of Li0.5+0.5 alphaFe2.5_1.5 alphaTialphaO4 re veal two prominent bands v(1) and v(1) and two weak bands v(3) and v(4 ) in the 700-200 cm(-1) range. The high frequency bands v(1) and v(2) are assigned to tetrahedral metal complexes. On the basis of the analy sis of the IR bands and their correlation with the cation distribution , the band v(3) is assigned to octahedral divalent metal ion-oxygen co mplexes, while the lowest frequency band v(4) is attributed to the lat tice vibrations in the mixed ferrites. The splitting of the IR spectra l band is explained on the basis of Fe2+ ion concentration.