High coercivity and high wear resistance &ggr;‐Fe2O3thin films are described, which were prepared by bias sputtering followed by heat treatments. The coercivity, squareness ratio, and wear resistance of the films were increased by applying a negative bias voltage of about −60 V to the substrate. The improvements in magnetic and mechanical properties are attributed to the enhanced ion irradiation which increased both the internal strain of the films and the strength with which the films adhered to the substrates. When the bias voltage was too low (−180 V), many cracks appeared in the film and this resulted in low coercivity and poor wear resistance. ©1995 American Institute of Physics.