An investigation was made of ZnO(00•1) single crystals annealed in high vacuum with respect to their magnetic properties and cluster formation tendency after implant-doping with Fe. While metallic Fe cluster formation was suppressed, no evidence for the relevance of the Fe magnetic moment to the observed ferromagnetism was found. The latter, together with cluster suppression, was considered with respect to defects in the ZnO host matrix, since the crystalline quality of the substrates was lowered due to the preparation as observed by X-ray diffraction.

Ferromagnetism and Suppression of Metallic Clusters in Fe Implanted ZnO: a Phenomenon Related to Defects? Zhou, S., Potzger, K., Talut, G., Reuther, H., Kuepper, K., Grenzer, J., Xu, Q., Mücklich, A., Helm, M., Fassbender, J., Arenholz, E.: Journal of Physics D, 2008, 41[10], 105011