We report on long-range spin wave (SW) propagation in nanometer-thick Yttrium Iron Garnet (YIG) film with an ultralow Gilbert damping. The knowledge of a wavenumber value | ⃗ | is essential for designing SW devices. Although determining the wavenumber | ⃗ | in experiments like Brillouin light scattering spectroscopy is straightforward, quantifying the wavenumber in all-electrical experiments has not been widely commented so far.We analyze magnetostatic spin wave (SW) propagation in YIG films in order to determine SW wavenumber | ⃗ | excited by the coplanar waveguide. We show that it is crucial to consider influence of magnetic anisotropy fields present in YIG thin films for precise determination of SW wavenumber. With the proposed methods we find that experimentally derived values of | ⃗ | are in perfect agreement with that obtained from electromagnetic simulation only if anisotropy fields are included.

We report on the correlation of structural and magnetic properties of Y3Fe5O12 (YIG) films deposited on Y3Al5O12 substrates using pulsed laser deposition. The recrystallization process leads to an unexpected formation of interfacial tensile strain and consequently strain-induced anisotropy contributing to the perpendicular magnetic anisotropy. The ferromagnetic resonance linewidth of YIG is significantly increased in comparison to a film on a lattice-matched Gd3Ga5O12 substrate. Notably, the linewidth dependency on frequency has a negative slope. The linewidth behavior is explained with the proposed anisotropy dispersion model.

We show that using maskless photolithography and the lift-off technique patterned yttrium iron garnet thin films possessing ultra-low Gilbert damping can be accomplished. The films of the 70 nm thickness were grown on (001)-oriented gadolinium gallium garnet by means of pulsed laser deposition and exhibit high crystalline quality, low surface roughness and effective magnetization of 127 emu/cm 3 . The Gilbert damping parameter is as low as 5 × 10 −4 . The obtained structures have well-defined sharp edges which along with good structural and magnetic film properties, pave a path in the fabrication of high-quality magnonic circuits as well as oxide-based spintronic devices.Yttrium iron garnet (Y 3 Fe 5 O 12 , YIG) has become an intensively studied material in recent years due to exceptionally low damping of magnetization precession and electrical insulation enabling its application in research on spin-wave propagation 1-3 , spin-wave based logic devices 4-6 , spin pumping 7 , and thermally-driven spin caloritronics 8 . These applications inevitably entail film structurization in order to construct complex integrated devices. However, the fabrication of high-quality thin YIG films requires deposition temperatures over 500C 6,[9][10][11][12][13][14][15][16][17][18] leading to top-down lithographical approach that is ion-beam etching of a previously deposited plain film whereas patterned resist layer serves as a mask.Consequently, this method introduces crystallographic defects, imperfections to surface structure and, in the case of YIG films, causes significant increase of the damping parameter. [19][20][21] Moreover, it does not ensure well-defined structure edges for insulators, which play a crucial role in devices utilizing

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We report on the Gilbert damping parameter α, the effective magnetization [Formula: see text], and the asymmetry of the g-factor in bottom-CoFeB(0.93 nm)/MgO(0.90-1.25 nm)/CoFeB(1.31 nm)-top as-deposited systems. Magnetization of CoFeB layers exhibits a specific noncollinear configuration with orthogonal easy axes and with [Formula: see text] values of [Formula: see text] kG and [Formula: see text] kG for the bottom and top layers, respectively. We show that [Formula: see text] depends on the asymmetry [Formula: see text] of the g-factor measured in the perpendicular and the in-plane directions revealing a highly nonlinear relationship. In contrast, the Gilbert damping is practically the same for both layers. Annealing of the films results in collinear easy axes perpendicular to the plane for both layers. However, the linewidth is strongly increased due to enhanced inhomogeneous broadening.

Aggregation of the polydopamine (PDA) molecular building blocks at the air/water interface leads to obtaining large surface nanometric-thin films. This mechanism follows two possible pathways, namely, covalent or non-covalent self-assembly, which result in a different degree of structure order and, consequently, different structural properties. Control of this mechanism could be vital for applications that require true self-support PDA free-standing films, for example, electrochemical sensing or membrane technology. Here, we are considering the impact of boric acid (BA) and Cu2+ ions on the mentioned mechanism exclusively for the free-standing films from the air/water interface. We have employed and refined our own spectroscopic reflectometry method to achieve an exceptionally high real-time control over the thickness growth. It turned out that BA and Cu2+ ions significantly impact the film growth process. Reduction of the nanoparticles size and their number was examined via UV–vis spectroscopy and transmission electron microscopy, showing a colossal reduction in the mean diameter of nanoparticles in the case of BA and a moderate reduction in the case of Cu2+. This modification is leading to significant enhancement of the process efficiency through moderation of the topological properties of the films, as revealed by atomic force microscopy. Next, applying infrared, Raman, and X-ray photoelectron spectroscopy, we presented small amounts of metal (B or Cu) in the final structure of PDA and simultaneously their vital role in the oxidation mechanism and cross-linking through covalent or non-covalent bonds. Therefore, we revealed the possibility of synthesizing films via the expected self-assembly mechanism which has hitherto been out of control. Moreover, modification of mechanical properties toward exceptionally elastic films through the BA-assisted synthesis pathway was shown by achieving Young’s modulus value up to 24.1 ± 5.6 and 18.3 ± 6.4 GPa, using nanoindentation and Brillouin light scattering, respectively.

The possibility of affecting the magnetic properties of a material by dielectric means, and vice versa, remains an attractive perspective for modern electronics and spintronics. Here, we report on epitaxial Bi(Fe 0.5 Mn 0.5 )O 3 thin films with exceptionally low Gilbert damping and magnetoelectric coupling above room temperature (< 400 K). The ferromagnetic order, not observed in bulk, has been detected with a total magnetization of 0.44 μ B /formula units with low Gilbert damping parameter (0.0034), both at room temperature. Additionally, a previously overlooked check-board ordering of oxygen vacancies is observed, providing insights on the magnetic and dielectric origin of the multifunctional properties of the films. Finally, intrinsic magnetodielectric behavior is observed as revealed by the variation of dielectric permittivity well above room temperature. These findings show the possibility of electric-field-controlled magnetic properties, in low Gilbert-damping-based spintronic devices, using single-phase multiferroic materials.

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