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Variation of magnetic properties through Cr substitution for Co in inverse-spinel CoFe2O4has been investigated by vibrating-sample magnetometry (VSM) and conversion electron Mssbauer spectroscopy (CEMS). CrxCo1-xFe2O4samples were prepared as thin films by a sol-gel method. The lattice constant of the CrxCo1-x- Fe2O4samples was found to remain unchanged, explainable in terms of a reduction of tetrahedral Fe3+ ion to Fe2+ due to substitution of Cr3+ ion into octahedral Co2+site. The existence of the tetrahedral Fe2+ ions in CrxCo1-xFe2O4 was confirmed by CEMS analysis. Room-temperature magnetic hysteresis curves for the CrxCo1-xFe2O4films measured by VSM revealed that the saturation magnetization (MS) increases by Cr doping. The MS is maximized when xand decreases for higher x but is still bigger than that ofCoFe2O4. The increase of MScan be explained partly by the reduction of the tetrahedral Fe3+ ion to Fe2+.