Magnetoresistance and IR spectrum of impurity states in the Ce$_{3}$Fe$_{5}$O$_{12}$ film

In polycrystalline cerium iron garnet films, the gap in the electron excitation spectrum and electronic transitions between di- and tetravalent iron and cerium impurity ions have been established from the IR absorption spectra. The temperatures of delocalization of the ferrous states of iron have been found from the impedance spectroscopy, electrical resistance, and IR spectroscopy data. The difference between the ac and dc magnetoresistances has been established and explained using a model of a dielectrically inhomogeneous medium.