Room temperature ferromagnetism in carbon-implanted ZnO
  Unexpected ferromagnetism has been observed in carbon doped ZnO films grown by pulsed laser deposition [Phys. Rev. Lett. 99, 127201 (2007)]. In this letter, we introduce carbon into ZnO films by ion implantation. Room temperature ferromagnetism has been observed. Our analysis demonstrates that (1) C-doped ferromagnetic ZnO can be achieved by an alternative method, i.e. ion implantation, and (2) the chemical involvement of carbon in the ferromagnetism is indirectly proven. 
Shengqiang Zhou, Qingyu Xu, Kay Potzger, Georg Talut, Rainer   Groetzschel, Juergen Fassbender, Mykola Vinnichenko, Joerg Gr...