Temperature dependences of the interlayer exchange constant of three-layer FeNi/Dy/FeNi films studied by the resonance method

Abstract

Three-layer FeNi/Dy/FeNi films were studied by ferromagnetic resonance method in the temperature range from 4 to 300 K. The acoustic and optical peaks recorded in microwave spectra demonstrate the presence of exchange coupling between the ferromagnetic FeNi layers of the planar system and allow us to establish the sign and value of the constant of the interlayer exchange interaction. Temperature dependences of the interlayer exchange interaction constant for three-layer films with intermediate layer thicknesses Dy 5 and 10 nm show a number of features (change in sign and extremum point), which reflect transformations of the magnetic structure Dy. Keywords: interlayer exchange coupling, helical magnetic structure, ferromagnetic resonance, three-layer films.