Ferromagnetism in transition-metal-doped TiO_2 thin films

V, Cr, Fe, Co, and Ni had been chosen to substitute partially for Ti in TiO_2. By applying appropriate conditions, transition-metal-doped TiO_2 thin films deposited on LaAlO_3 substrates by laser ablation which show a good crystallinity and ferromagnetism above room temperature, could be obtained. The tendency of the dependence of magnetization versus element seems to be in accord with what theories have predicted. Among all the dopants, V appears to be the most promising candidate since its doping results in semiconducting films with a giant magnetic moment. Films are free of dopant particles or clusters. Structural and magnetic measurements have revealed that the room temperature ferromagnetism in V/Cr/Fe/Co/Ni-doped thin films must originate from the transition-metal-doped TiO_2 matrices