Instytut Fizyki Molekularnej Polskiej Akademii Nauk


Wydarzenie w dniu 26.05.2023:

Oddziału Fizyki Magnetyków i Zjawisk Kooperatywnych

Dnia: 26.05.2023 roku (piątek)
o godzinie 10:00 w auli Instytutu

referat pt.:

Probing spin waves in individual magnetic nanoelements


prof. dr Gleb Kakazei

Univerity of Porto

A series of our recent experiments on individual nanomagnets fabricated using focused electron beam induced deposition (FEBID) will be discussed. First, an original spatially resolved approach for spin-wave spectroscopy of individual circular magnetic elements with sample volumes down to about 10−3 μm3 will be presented [1]. The key component of the setup is a coplanar waveguide whose microsized central part is placed over a movable substrate with well-separated CoFe-FEBID nanodisks which exhibit standing spin-wave resonances. The circular symmetry of the disks allows for the deduction of the saturation magnetization and the exchange stiffness of the material using
an analytical theory. Next, using this approach, the engineering of the magnetic properties of CoFe-based nanodisks fabricated by FEBID will be demonstrated [2]. The material composition in the nanodisks was tunedin situvia the e-beam waiting time in the FEBID process and their post-growth irradiation with Ga ions. The achieved saturation magnetization Ms variation in the broadmrange from 720 to 1430 emu/cm3 continuously bridges the gap between the values of widely used magnonic materials such as Permalloy and CoFeB. Further, nanovolcanoes - nanodisks overlaid by nanorings – will be introduced as purpose-engineered 3D architectures for nanomagnonics [3].
The extension of 2D nanodisks into the third dimension allows for engineering their lowest eigenfrequency with 30% smaller footprints. The nanovolcanoes can be viewed as multi-mode microwave resonators and 3D building blocks for nanomagnonics. Finally, spin-wave phase
shifters upon a single nanogroove milled by a focused ion beam in a Co–Fe microsized magnonic waveguide, characterized by all-electrical spin-wave spectroscopy, will be described [4]. By varying the groove depth and the in-plane bias magnetic field, we continuously tune the spin-wave phase and experimentally evidence a complete phase inversion. The proposed phase shifter can easily be on-chip integrated with spin-wave logic gates and other magnonic devices.
[1] O.V. Dobrovolskiy et al., Spin-wave spectroscopy of individual ferromagnetic nanodisks,
Nanoscale 12, 21207 (2020).
[2] S.A. Bunyaev et al., Engineered magnetization and exchange stiffness in direct-write Co–Fe nanoelements, Appl. Phys. Lett., 118, 022408 (2021).
[3] O.V. Dobrovolskiy et al., Spin-wave eigenmodes in direct-write 3D nanovolcanoes, Appl.
Phys. Lett., 118, 132405 (2021).
[4] O.V. Dobrovolskiy, et al., Spin-wave phase inverter upon a single nanodefect, ACS Appl.
Mater. Interfaces, 11, 17654 (2019).

Tło strony

Żel fizyczny utworzony przez żelator methyl-4,6-O-(p-nitrobenzylidene)-α-D-glukopyranozę z butanolem w stężeniu 2%, obraz z polaryzacyjnego mikroskopu optycznego