FEATURES OF EXCHANGE COUPLING BETWEEN PERMALLOY LAYERS WITHIN FeNi/Dy/FeNi THREE-LAYER FILMS WITHIN THE TEMPERATURE RANGE FROM 4 TO 300 K

DOI: 10.47475/2500-0101-2025-10-3-595-604

FeNi/Dy/FeNi three-layer films were studied by the ferromagnetic resonance method in the temperature range from 4 to 300 K. Acoustic and optical peaks detected in the microwave spectra indicated the presence of exchange coupling between the ferromagnetic FeNi layers in the planar structure, which allowed determining the sign and value of the interlayer exchange interaction constant J12. The temperature dependence of J12 of the three-layer film with the thickness of Dy interlayer equal to 15 nm demonstrated a number of features (a change in the sign and an extremum point of the J12(T) function), which was indicative of transformations of the Dy magnetic structure.