Ferromagnetism Induced by Oxygen Vacancies in Zinc Peroxide Nanoparticles

Abstract

A correlation between oxygen vacancies and the magnetization for pure zinc peroxide nanoparticles (∼7 nm) synthesized by the hydrothermal method is demonstrated. Occurrence of room temperature ferromagnetism for zinc peroxide nanoparticles is established by the observed hysteresis loops and the ferromagnetic resonance signal. X-ray photoelectron spectroscopy and photoluminescence results reveal the oxygen insufficiency in the samples. The variation of oxygen vacancies concentration is consistent with the changes of the saturation magnetization for the samples. Combining with the results of electron spin resonance, it is suggested that the singly occupied oxygen vacancies forming the F+ centers play the key role in the exchange mechanism.