Magnetoresistance of antiferromagnetic metals with localized magnetic moments

The magnetoresistance (MR) of antiferromagnetic rare‐earth hexaborides (ReB6) (Re=Pr, Nd, Gd, and Dy) have been experimentally studied in magnetic fields up to 30 kOe in the temperature range from 4 to 30 K. The MR in general is positive and increases with increasing field for temperature below the Neel temperature (TN) and above TN the MR is negative. A large drop in the MR is observed at the antiferromagnetic to paramagnetic phase transition temperatures. We have also observed an anisotropy in the logitudinal and transverse magnetoresistances of ReB6 compounds except for GdB6. This is thought to be caused by anisotropic conduction electron  f ‐electron interactions. The experimental results are discussed in light of existing theories.