Structural, electrical, optical and magnetic properties of Co _0.2 Al _x Zn _0.8-x O films

Co _0.2 Al _x Zn _0.8-x O films prepared with different molar ratio of aluminum nitrate to zinc acetate were deposited on substrates by the sol-gel technique. X-ray diffraction, photoluminescence and ferromagnetism measurements were used to characterize the Co _0.2 Al _x Zn _0.8-x O diluted magnetic semiconductors. The authors found that the intensity of the acceptor-related photoluminescence increased with increasing aluminum concentration and an increase in the number of the acceptor-like defects (zinc vacancies especially) in the Co _0.2 Al _x Zn _0.8-x O film might lead to the enhancement of the magnetic properties. This implies that controls of the aluminum concentration and the number of the acceptor-like defects are important factors to produce strong ferromagnetism Co _0.2 Al _x Zn _0.8-x O films prepared by the sol-gel method.