Determination of the single-ion anisotropy in Cd1−xCoxS using optical Faraday rotation technique at T = 80 mK

The single-ion anisotropy constant D of Co 2+ in Cd 1− x Co x S was determined from a magnetization step which was detected using optical Faraday rotation technique. Experiments were performed in a dilution refrigerator at a temperature of approximately 80mK. Analysis of the data gave D / k B = 0.96 ± 0.02 K .