Magnetism, spintronics

Shift of resonance frequencies of Stokes and anti-Stokes lines in Mandelstam–Brillouin spectra with changing interface in NiFe|Spacer|IrMn exchange-biased thin films

M. V. Bahmetev^a, A. V. Sadovnikov^b, V. A. Gubanov^b, V. V. Savin^c, R. B. Morgunov<sup>ad

a</sup> Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry, Russian Academy of Sciences, Chernogolovka, Moscow region
^b Saratov State University
^c Immanuel Kant Baltic Federal University, Kaliningrad
^d Tambov State Technical University

Abstract: Spin-waves in NiFe/Cu/IrMn and NiFe/Ta/IrMn heterostructures with variable thickness of copper and tantalum interlayers were studied by Brillouin Light Scattering (BLS). Resonance frequencies of the Stokes and anti-Stokes lines shift upon inversion of the external magnetic field. When the percolation threshold is reached in the interlayer, the sign of the frequency shift changes and remains negative until a continuous coating is achieved. Complete rupture of the direct exchange contact between the NiFe and IrMn layers by the non-magnetic material of the interlayer leads to a zero shift of the resonant scattering frequencies. Changes in the resonant frequencies of spin-wave scattering characterize the quality of the NiFe/Spacer/IrMn interface, the fractal dimension of which corresponds to the three-dimensional structure.

Keywords: exchange bias, spacer, Mandelstam–Brillouin scattering spectra, shift of scattering resonance frequencies.

Received: 30.04.2025
Revised: 15.05.2025
Accepted: 25.05.2025

DOI: 10.61011/FTT.2025.06.60945.104-25

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