Effect of oxygen vacancies on the electrical transport properties of conductive Y₃Fe₅O₁₂ films at high temperature

Oxygen vacancies doping in oxide materials is a very common means to modulate the electrical transport properties. In this work, Y₃Fe₅O₁₂ (YIG) films with abundant oxygen vacancies were grown on Gd₃Ga₅O₁₂ substrates by solution spin coating and high vacuum annealing method, and the effect of oxygen vacancies on the electrical transport properties was systematically studied. It was found that a large amount of oxygen vacancies doping could convert the YIG film from a good room-temperature insulator to an electrical conductor. At high temperature and high vacuum, a large number of oxygen vacancies increased the disorder of the system, resulting in the appearance of a band-tail state, thus forming a constant range hopping conduction. While when the sample was exposed to air, the oxygen vacancies in the sample would gradually recombine and disappear, and the conduction mechanism transferred to drift mode.