INTRINSIC ROOM TEMPERATURE FERROMAGNETISM OF SILICON-DOPED ZnO THIN FILMS

We report our study on the magnetic properties of Si -doped ZnO thin films fabricated by pulsed laser deposition technique. The Si -doped ZnO thin films show ferromagnetism at room temperature. The saturation magnetism increases from 0 to 2.4 emu/cc with the increasing of Si concentration up to 2%, and then decreases with further increasing of Si concentration. First-principles calculation demonstrates that the origination of ferromagnetism for Si -doped ZnO system is the two unpaired electrons of Si -2p. These unpaired electrons increase the magnetic moments which are responsible for the increasing ferromagnetism.