Magnetic evolution of nickel ion doped In2O3 nanocrystals under high magnetic field

High magnetic field (HMF) treatment is an important strategy to tune the physicochemical properties of traditional materials. Here, we take nickel ion doped In2O3 nanocrystals as an example and report that the magnetization behavior of diluted magnetic semiconductors can be easily tuned by HMF treatment. It is experimentally demonstrated that the room temperature ferromagnetism of lowly-doped nanocrystals can be greatly enhanced by HMF treatment while the paramagnetic properties of highly-doped samples is almost un-changed. These magnetic transition behaviors after HMF treatment are attributed to the rearrangement of magnetic ordering and the increment of grain-boundary defects. Our research not only points out an effective approach to induce the transition of spin states of diluted magnetic semiconductors but also provides a potentially efficient route to endow other traditional materials with novel physical properties.