Manifestation of unidirectional exchange anisotropy in ferrite-garnet films with a “weak” sublattice

Ferrite-garnet films of submicron thickness were investigated by ferromagnetic resonance method. It was found that the magnetization of the sample in perpendicular to the surface of the film magnetic field showed an abnormal change in the magnetization and also rotation of the magnetic axis. This behavior of a ferromagnetic material in the presence of a magnetic field can be explained by the expressions for the linear magnetostrictive effect, and the piezomagnetic effect arising from the para-processes operating within a “weak” rare-earth magnetic sublattice which is located inside a unidirectional exchange field of “strong” iron sublattice.