Magnetoresistance of antiferromagnetic metals with localized magnetic moments

摘要

The magnetoresistance (MR) of antiferromagnetic rarehyphen;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 Neacute;el temperature (TN) and aboveTNthe 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 ReB6compounds except for GdB6. This is thought to be caused by anisotropic conduction electron thinsp;fthinsp;hyphen;electron interactions. The experimental results are discussed in light of existing theories.