Room temperature magnetism in sputtered (Zn,Co)O films

Cobalt doped zinc oxide films Zn/sub 1-x/Co/sub x/O with the atomic fraction x in the range 0.035-0.115 were prepared by sputtering from composite ZnO/Co/sub 3/O/sub 4/ targets. X-ray diffraction pattern shows the ZnO phase with [002] preferential orientation. Magnetic measurements show ferromagnetic behavior with Curie temperatures higher than 350 K.