Impurity concentration study on ferromagnetism in Cu-doped thin filmsDeng Lu Hou, Hai Juan Meng, Li Yun Jia, Xiao Juan Ye, Hong Juan Zhou and Xiu Ling Li
College of Physic Science and Information Engineering, Hebei Normal University - Shijiazhuang 050016, China
received 6 February 2007; accepted in final form 2 May 2007; published June 2007
published online 24 May 2007
We report here the observation of significant room-temperature ferromagnetism in a semiconductor doped with nonmagnetic impurities, Cu-doped rutile thin films grown by reactive magnetron sputtering. Films annealed in air were nonmagnetic while those annealed in vacuum were ferromagnetic with a Curie temperature about 350 K. The magnetic moment per copper atom decreased as the copper concentration increased. These results show that both the oxygen vacancies and the distance between nearest-neighbor copper atoms play a crucial role for the appearance of magnetism.
75.50.Pp - Magnetic semiconductors.
75.70.-i - Magnetic properties of thin films, surfaces, and interfaces.
74.25.Ha - Magnetic properties.
© Europhysics Letters Association 2007