Physics

Features of exchange coupling between permalloy layers within FeNi/Dy/FeNi three-layer films within the temperature range from $4$ to $300$ K

I. G. Vazhenina^a, R. S. Iskhakov^b, S. V. Stolyar^c, V. Yu. Yakovchuk<sup>d

a</sup> Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russia
^b Siberian Federal University, Krasnoyarsk, Russia
^c Samarkand State University named after Sharof Rashidov, Samarkand, Uzbekistan
^d Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia

Abstract: 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 $J_{12}$. The temperature dependence of $J_{12}$ 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 $J_{12}(T)$ function), which was indicative of transformations of the Dy magnetic structure.

Keywords: interlayer exchange interaction, helicoidal magnetic structure, ferromagnetic resonance, three-layer films.

UDC: 537.6

Received: 30.04.2025
Revised: 28.06.2025

Language: English

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