Temperature-dependent paramagnetic susceptibilities of Cu2+ and Co2+ as dilute impurities in ZnO -: art. no. 104411

The temperature-dependent magnetic susceptibilities of Cu2+:ZnO have been measured and successfully analyzed on the basis of crystal field theory including the dynamic Jahn-Teller effect. The susceptibility behavior near 154 K suggests that there are small amounts of Cu in antiferromagnetic clusters in the crystal. The analysis determines electronic and vibronic constants of the perturbed Cu2+ ion. The simple crystal field model is not successful for the analysis of the temperature dependence of the susceptibilities of Co2+:ZnO at low temperatures. Agreement between calculated and observed susceptibilities is possible if it is assumed that there are a small number of Co ferromagnetic clusters in the crystal. Effective Curie temperatures for the clusters are determined from the analysis.