In this work, magnetic properties and thermal stability of antiferromagnetically coupled AFC medium with a CrMo spacer layer instead of the conventional Ru spacer layer were studied. It was found that a reduction of Mr/Ms could also be obtained in the AFC medium with a CrMo spacer layer due to the antiferromagnetic coupling, similar to the conventional AFC medium with a Ru spacer layer. Thermal stability ratio, KUV/kBT for the proposed medium was slightly smaller than that of the conventional AFC medium with a Ru spacer layer, but larger than that of a single magnetic layer medium. By a comparison of the switching field distribution and ΔM of the AFC medium with those of the conventional AFC medium, it is conjectured that the intergranular exchange coupling decreases when a CrMo is used as a spacer layer. © 2003 American Institute of Physics.