arXiv subjects

A. Trzaskowska

Publications and source records attributed to A. Trzaskowska.

5 recordsLinked to original sources

arXiv2026

Independent Tuning of Surface Acoustic-Waves and Spin-Waves via Buffer-Layer Engineering in Co2FeGe Heusler Thin Films

Understanding and controlling acoustic and spin-wave excitations in magnetic thin films is critical for the development of magnonic and spin-acoustic devices. We report on the use of Cr and W buffer layers to independently modify the acoustic and magnetic excitations in Co2FeGe full-Heusler thin films grown on MgO(001). Using Brillouin light scattering (BLS) spectroscopy and ferromagnetic resonance (FMR), we probed Rayleigh and Sezawa surface acoustic waves (SAWs) alongside Damon-Eshbach and perpendicular standing spin-wave (PSSW) modes. Our results show that acoustic dispersion depends strongly on the buffer material; W-buffered films exhibit a pronounced 16% reduction in Rayleigh SAW frequency compared to buffer-free films, primarily due to mass loading and acoustic impedance shifts. While the buffer layers significantly shift acoustic frequencies, they simultaneously modify the dynamic magnetic response (increasing spin-wave group velocity by ~34%) through different physical mechanisms. Finite-element simulations show excellent agreement with the experimental acoustic data. These findings demonstrate that buffer-layer engineering is an effective strategy for the independent tailoring of elastic and magnetic excitations, providing a versatile platform for hybrid spin-acoustic technologies.

cond-mat.mtrl-sci↗

arXiv2025

Elastic anisotropy and Surface Acoustic Wave propagation in CoFeB/Au multilayers: influence of thickness and light penetration depth

Surface acoustic waves in multilayered nanostructures represent a critical frontier in understanding material behavior at the nanoscale, with profound implications for emerging acoustic and spintronic technologies. In this study, we investigate the influence of the magnetic layer thickness on the propagation of surface acoustic waves in CoFeB based multilayers. Two approaches to effective medium modelling are considered: one treating the entire multilayer as a homogeneous medium and another focusing on the region affected by light penetration. The elastic properties of the system are analyzed using Brillouin light scattering and numerical modelling, with a particular emphasis on the anisotropy of Young s modulus and its dependence on CoFeB thickness. The results reveal a significant variation in surface acoustic wave velocity and elastic anisotropy as a function of the multilayer configuration, highlighting the role of the penetration depth in effective medium approximations. These findings provide valuable insights into the tunability of acoustic and spin-wave frequencies through structural modifications, which is crucial for the development of high-performance resonators, surface acoustic wave filters, and spin-wave-based information processing devices.

cond-mat.mtrl-sci↗

arXiv2024

Spin waves in Co$_2$FeGe films

The dynamic magnetic properties of Full Heusler alloy thin films of Co$_2$FeGe, grown on MgO (001) substrates under different thermal conditions, were investigated. Brillouin light scattering and ferromagnetic resonance measurements revealed that depositing at room temperature followed by annealing at 300 deg C for 1 hour produces the best results for maximizing magnetization, exchange stiffness, and minimizing spin-dynamic dissipation in the films, which are desirable characteristics for high-speed spintronic devices. Additionally, strong hybridization of spin waves in the Damon-Eshbach geometry was observed, which is attractive for applications in magnonic signal processing circuits.

cond-mat.mtrl-sci↗

arXiv2024

The studies on phonons and magnons in (Ni80Fe20/Au/Co/Au) multilayers of different number of repetitions

In Ni80Fe20/Au/Co/Au deposited on silicon substrate the interaction between spin waves and surface acoustic waves is observed by Brillion light scattering spectroscopy. We show that by changing the number of receptions in the multilayer we can tune the dispersion of surface acoustic waves (SAWs) not affecting significantly fundamentals spin wave (SW) mode. As a result, we can control (activate or deactivate) the magnetoelastic interaction between fundamental SW mode and SAWs by the thickness of the magnetostrictive multilayer.

cond-mat.mtrl-sci↗

arXiv2024

Investigation of phonons and magnons in [Ni80Fe20/Au/Co/Au]N multilayers

The interaction between phonons and magnons is a widely developing topic, especially in the field of acoustic spintronics. To discuss this interaction, it is necessary to observe two different waves (acoustic and spin waves) with the same frequency and wavelength. In the Ni80Fe20/Au/Co/Au system deposited on a silicon substrate, we observe the interaction between spin waves and surface acoustic waves using Brillouin light scattering spectroscopy. As a result, we can selectively control (activate or deactivate) the magnetoelastic interaction between the fundamental spin wave mode and surface acoustic waves by adjusting the magnetostrictive layer thickness in the multilayer. We demonstrate that by adjusting the number of layers in a multilayer structure, we can precisely control the dispersion of surface acoustic waves, with minimal impact on the fundamental spin wave mode

cond-mat.mtrl-sci↗