Magnetic Behavior of CuMn Dilute Alloys

The electron-spin resonance of CuMn dilute alloys was observed for samples annealed in an ultra-highvacuum system. An anomaly in the ESR linewidth for 4.3 and 2.0 at.% Mn alloys was observed in the temperature region where Kouvel observed an anomaly in the resistivity. This anomaly should be considered as an effect of magnetic short-range order among the diluted Mn atoms. The antiferromagnetic phase transition temperature $T_N$ was estimated from the temperature variation of the resonance position. The $T_N$ was about 60 and 20°K for the 4.3 and 2.0 at.% Mn alloys, respectively.