Magnetic and transport properties of transition-metal implanted ZnO single crystals R.P. Borges, B. Ribeiro, A.R.G. Costa, C. Silva, R.C. da Silva, G. Evans, A.P. Gonçalves, M.M. Cruz, M. Godinho and U. Wahl Eur. Phys. J. B, 85 3 (2012) 91 Published online: 07 March 2012 DOI: 10.1140/epjb/e2012-30089-y