Room temperature ferromagnetism in Cu-doped ZnO synthesized from CuO and ZnO nanoparticles

AC susceptibility and ferromagnetic resonance (FMR) measurements indicate that ZnO doped with Cu by a simple sintering process starting from nanoparticles of ZnO and CuO is ferromagnetic above room temperature. FMR measurements above room temperature indicate the ordering temperature to be above 520 K. The observation supports the recent theoretical calculations of Huang et al. which predict ferromagnetism in copper-doped ZnO.