Anomalous colossal magnetoresistance effect in the Zn-doped Fe1-xZnxCr2S4 polycrystals with the spinel structure

The electrical resistivity, magnetization, and magnetoresistance effect have been studied on a series of Zn-doped polycrystalline samples Fe1-xZnxCr2S4 (0 less than or equal tox less than or equal to1) with a spinel structure over a wide range of composition and temperature. It is found that the magnetism and magnetoresistance ratio are anomalous, which do not change monotonically with substituting nonmagnetic Zn2+ ions in place of Fe2+ ions. Considering the effect of the applied magnetic field and substitution of Fe2+ by Zn2+ ions on the magnetism and small polarons transport property, the anomalous magnetism and magnetoresistance effect can be explained. (C) 2001 American Institute of Physics.