Role of defects in tuning ferromagnetism in diluted magnetic oxide thin films

In order to answer the question of whether there is another source of magnetism that plays an important role in tuning ferromagnetism in diluted magnetic oxide thin films, investigations on magnetic and structural properties of some types of transition-metal-doped semiconductors had been done. Results on Cr-doped ZnO and Ni-doped SnO2 films fabricated under various conditions implied that structural defects and/or oxygen vacancy, indeed, very much influence the magnetism in those systems. An elimination of defects, as well as filling up oxygen vacancies, might cause certain degradation to the ferromagnetic ordering of some specific types of compounds.