Study on Mossbauer Signature, Hyperfine Interaction Parameters and Removal of Delafossite Phase of Al3+-Modified Copper Ferrite

The effect of Al3+ substitution on Mossbauer signature and hyperfine interaction parameters of copper ferrite (CuFe2O4) is studied at 300 K. The X-ray powder diffraction pattern analysis shows that all the four compositions of the ferrite system, CuAl (x) Fe2-x O-4 (x = 0.0, 0.2, 0.4, and 0.6), have single-phase fcc spinel structure. On the other hand, Mossbauer spectral analysis reveals that x = 0.0 and 0.2 compositions possess paramagnetic singlet of delafossite (CuFeO2) phase along with two magnetic sextets of spinel ferrite phase. On Al3+ substitution for Fe3+ in the system (x a parts per thousand yen 0.4), formation of this secondary unwanted phase of CuFeO2 is found to be prevented. The hyperfine interaction parameters are determined and found to be influenced by Al3+ substitution. The noncollinear spin arrangement in the system is verified and the actual cationic distributions are suggested.