Grain boundary ferromagnetism in vanadium-doped In

Room temperature ferromagnetism was observed in In2O3 thin films doped with 5 at.% V, prepared by pulsed-laser deposition at substrate temperatures ranging from 300 to $600\ ^\circ\text{C}$ . X-ray absorption fine-structure measurement indicated that V was substitutionally dissolved in the In2O3 host lattice, thus excluding the existence of secondary phases of V compounds. Magnetic measurements based on SQUID magnetometry and magnetic circular dichroism confirm that the magnetism is at grain boundaries and also in the grains. The overall magnetization originates from the competing effects between grains and grain boundaries