Fe implanted ferromagnetic ZnO
  Room-temperature ferromagnetism has been induced within ZnO single crystals by implant-doping with Fe ions. For an implantation temperature of 620 K and an ion fluence of 4x10^16 cm^-2, very tiny Fe particles, formed inside the host matrix, are responsible for the ferromagnetic properties. They were identified using synchrotron X-ray diffraction and Moessbauer spectroscopy. On the other hand, Fe ions implanted at a temperature of 253 K and an ion fluence of 4x10^15 cm^-2 are incorporated into the host matrix and develop a room temperature diluted magnetic semiconductor (DMS). 
K. Potzger, Shengqiang Zhou, H. Reuther, A. Muecklich, F. Eichhorn, N.   Schell, W. Skorupa, M. Helm, J. Fassbender, T. Herr...