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Abstract The structure and magnetic properties of the chemical composition Mn1-xCuxFe1.7Ga0.3O4 (x = 0, 0.25, 0.5, 0.75 and 1) were studied for all samples synthesized using two different techniques, standard solid-state reaction method and sol- gel method, also the cation distribution for the two samples (MnFe2O4 and CuFe2O4) were determined . XRD data showed that, all the samples have the cubic spinel structure except two samples (CuFe2O4 and CuFe1.7Ga0.3O4) where found a tetragonal structure. The lattice parameter increases with increasing copper content x. FTIR spectra showed that, two modes have appeared at (482-399) and (745-599) cm-1 corresponding to υ1 and υ2, respectively. These bands are assigned to the vibrations of the tetrahedron and octahedron for the trivalent (Fe3+) cation respectively. First mode is attributed to the stretching vibrations of tetrahedrally coordinated Fe3+-O2− bonds and second mode is attributed to the metal oxygen vibrations in the octahedral sites (B). The Mӧssbauer spectra at room temperature for Mn1-xCuxFe1.7Ga0.3O4 were decomposed into two components-Zeeman sextets, due to the Fe ions in the oxidation state Fe3+, in both A- and B-sites of the spinel structure. In addition to these two sextets, the spectra show a quadrupole doublet in the compound Mn1-xCuxFe1.7Ga0.3O4. This doublet may be due to the ferrite CuFeO2, which is paramagnetic at room temperature. The isomer shifts of A-sites are slightly larger than those of B-sites except for the sample (CuFe1.7Ga0.3O4). In contrast the internal magnetic fields of Asites are slightly smaller than those of B-sites. The cation distribution were found as (Cu0.1Fe0.9) [Cu0.9 Fe1.1] , (Mn0.7Fe0.3) [Mn0.3 Fe1.7] for the simple ferrite samples where parenthesis refers to the tetrahedral A-site and square bracket refers to the octahedral B-site. The saturation magnetization (MS) in samples prepared using solid state reaction was found (from 14.071 to 46.122 emu/g). We found that, MS increases with Cu content up to x = 0.5 and then gradually decreases with further increase of Cu content and for samples prepared using solgel method was found (17.949 to 39.963 emu/g). Also the observed moments were compared to the theoretically calculated moments according to Néel model and depending on different possible cation distribution. The results clearly suggest that Ga3+ cation distributed in both A site and B- sites and this was in agreement with the Mӧssbauer data. |