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 and M. Godinho Eur. Phys. J. B, 79 2 (2011) 185-195 Published online: 23 December 2010 DOI: 10.1140/epjb/e2010-10512-3