Abnormal phase transition and magnetic properties in Cu, Fe co-doped In2O3 nanocrystals

Fe, Cu co-doped In2O3 nanocrystals were synthesized by a coprecipitation method. Phase analyses revealed that Fe ions have high solubility (up to 15.4at.%) in the In2O3 matrix, while the Cu ions strongly restrain In2O3 phase transition from cubic to hexagonal. Raman spectroscopy shows that by adding Cu ions, the defect concentration increases. The samples show no evidence of ferromagnetism by additional Cu doping, indicating that Cu content might be a key point to realize room temperature ferromagnetism in Fe doped In2O3.