The origin of ferromagnetism and defect-magnetization correlation in nanocrystalline ZnO

We report here experimental results that clearly indicate that defects govern the room temperature magnetic property of nanocrystalline ZnO. The nanocrystalline ZnO has been found to exhibit a paramagnetic behaviour at room temperature but becomes ferromagnetic once oxygen defects are introduced in it. It has been shown further that cation defects in nanocrystalline ZnO makes it more diamagnetic.