Influence of oxygen vacancies on magnetic and transport properties of thin Zn_1-xCo_xO_y films

Abstract

Abstract. The features of the structural, transport and magnetic properties of thin Zn 1-x Co x O y films (x=0-0.45), fabricated on с-sapphire substrates by the pulsed laser deposition method are studied. It is found that the transport and ferromagnetic properties of the wurtzite Zn 1-x Co x O y films nonmonotonously depend on Co concentration at room temperature. For the Zn 0.87 Co 0.13 Oy film, the strongest ferromagnetic signal is observed that is caused by formation of the greatest number of metallic Co clusters. A further increase of doping impurity concentration in the films leads to the oxidation of metallic Co and formation of the paramagnetic Co 3 O 4 phase, in consequence of which the ferromagnetic signal subsides.