scholarly journals The angular dependence of magnetization dynamics induced by a GHz range strain pulse

2022 ◽  
Author(s):  
Kakeru Tojo ◽  
Akira NAGAKUBO ◽  
Hirotsugu OGI
Keyword(s):  
Magnetic Field ◽  
Angular Dependence ◽  
Spin Wave ◽  
Echo Signal ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Wave Resonance ◽  
Out Of Plane ◽  
Magneto Optical Kerr Effect ◽  
Strain Pulse

Abstract The dynamics of magnetization is important in spintronics, where the coupling between phonon and magnon attracts much attention. In this work, we study the angular dependence of the coupling between longitudinal-wave phonon and magnon. We investigated the magnetization dynamics using the time-resolved magneto-optical Kerr effect, which allows measuring spin-wave resonances and the magnetic echo signal. The frequency, mode number, and amplitude of the spin-wave resonance change with the out-of-plane angle of the external magnetic field. The amplitude of the magnetic echo signal caused by the strain pulse also changes with the angle. We calculate these angular dependences based on the Landau-Lifshitz-Gilbert equation and find that the angles of the external field and magnetic moment are important factors for the phonon-magnon coupling when phonon propagates in the thickness direction under the out-of-plane magnetic field.

scholarly journals Bi-reflection of spin waves

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Tomosato Hioki ◽  
Yusuke Hashimoto ◽  
Eiji Saitoh
Keyword(s):  
Spin Wave ◽  
Elastic Waves ◽  
Light Wave ◽  
Incident Angle ◽  
Spin Waves ◽  
Time Resolved ◽  
Reflected Light ◽  
Sample Edge ◽  
Out Of Plane ◽  
Angle Of Reflection

Abstract When a light wave is refracted at a boundary between two different media, it may split into two rays due to optical anisotropy, a phenomenon called birefringence. On the other hand, for a reflected light wave in an ordinary medium, the angle of reflection is always the same as the incident angle as expected from the law of reflection. Here, we report the observation of a split of reflected spin-waves, or bi-reflection of spin-waves, where a spin-wave refers to a wavy motion of electron spins in a magnetic material. We measured the spin-wave propagation in a magnetic garnet Lu2Bi1Fe3.4Ga1.6O12 by using time-resolved magneto-optical microscopy and found that the spin-wave splits in two as a result of reflection at the sample edge of an out-of-plane magnetized film. Systematic measurements combined with calculations unveiled that the bi-reflection is due to the hybridization with elastic waves.

Resonant Amplification of Intrinsic Magnon Modes and Generation of New Extrinsic Modes in a Two-Dimensional Array of Interacting Multiferroic Nanomagnets by Surface Acoustic Waves

Nanoscale ◽  
2021 ◽  
Author(s):  
Anulekha De ◽  
Justine Lynn Drobitch ◽  
Sudip Majumder ◽  
Saswati Barman ◽  
S. Bandyopadhyay ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Spin Wave ◽  
Acoustic Waves ◽  
Kerr Effect ◽  
Surface Acoustic Waves ◽  
Optical Kerr Effect ◽  
Two Dimensional ◽  
Time Resolved ◽  
Magneto Optical Kerr Effect

Using time-resolved magneto optical Kerr effect (TR-MOKE) microscopy, we demonstrate surface-acoustic-wave (SAW) induced resonant amplification of intrinsic spin-wave (SW) modes, as well as generation of new extrinsic or driven modes...

scholarly journals Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

2018 ◽  
Vol 9 ◽  
pp. 1123-1134 ◽  
Author(s):  
Anulekha De ◽  
Sucheta Mondal ◽  
Sourav Sahoo ◽  
Saswati Barman ◽  
Yoshichika Otani ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin Wave ◽  
Lattice Constant ◽  
Magnetic Storage ◽  
Magnetization Dynamics ◽  
Bias Magnetic Field ◽  
Potential Applications ◽  
Ultrafast Magnetization ◽  
Antidot Arrays ◽  
Wave Modes

Ferromagnetic antidot arrays have emerged as a system of tremendous interest due to their interesting spin configuration and dynamics as well as their potential applications in magnetic storage, memory, logic, communications and sensing devices. Here, we report experimental and numerical investigation of ultrafast magnetization dynamics in a new type of antidot lattice in the form of triangular-shaped Ni80Fe20 antidots arranged in a hexagonal array. Time-resolved magneto-optical Kerr effect and micromagnetic simulations have been exploited to study the magnetization precession and spin-wave modes of the antidot lattice with varying lattice constant and in-plane orientation of the bias-magnetic field. A remarkable variation in the spin-wave modes with the orientation of in-plane bias magnetic field is found to be associated with the conversion of extended spin-wave modes to quantized ones and vice versa. The lattice constant also influences this variation in spin-wave spectra and spin-wave mode profiles. These observations are important for potential applications of the antidot lattices with triangular holes in future magnonic and spintronic devices.

scholarly journals Ultrafast magnetization dynamics in a nanoscale three-dimensional cobalt tetrapod structure

Nanoscale ◽  
2018 ◽  
Vol 10 (21) ◽  
pp. 9981-9986 ◽  
Author(s):  
Sourav Sahoo ◽  
Sucheta Mondal ◽  
Gwilym Williams ◽  
Andrew May ◽  
Sam Ladak ◽  
...  
Keyword(s):  
Spin Wave ◽  
Numerical Study ◽  
Spin Dynamics ◽  
Three Dimensional ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Complex Spin ◽  
Ultrafast Magnetization ◽  
Wave Modes

Time resolved measurement and numerical study of ultrafast spin dynamics in a 3D Co tetrapod structure revealed complex spin-wave modes.

scholarly journals Spin wave non-reciprocity and beating in permalloy by the time-resolved magneto-optical Kerr effect

2014 ◽  
Vol 47 (38) ◽  
pp. 385002 ◽  
Author(s):  
Siddharth Rao ◽  
Jungbum Yoon ◽  
Jan Rhensius ◽  
Charanjit S Bhatia ◽  
Hyunsoo Yang
Keyword(s):  
Spin Wave ◽  
Kerr Effect ◽  
Optical Kerr Effect ◽  
Time Resolved ◽  
Magneto Optical Kerr Effect

Angular dependence of spin wave resonance in FeNi–MgO granular film

2021 ◽  
Vol 118 (21) ◽  
pp. 212401
Author(s):  
Yongyong Cai ◽  
Hongmei Feng ◽  
Chengkun Song ◽  
Yabin Niu ◽  
Yuchen Ye ◽  
...  
Keyword(s):  
Angular Dependence ◽  
Spin Wave ◽  
Granular Film ◽  
Spin Wave Resonance ◽  
Wave Resonance

scholarly journals Ferromagnetic and spin wave resonances in thin layer of expanded austenite phase

2014 ◽  
Vol 32 (2) ◽  
pp. 198-205 ◽  
Author(s):  
J. Typek ◽  
N. Guskos ◽  
G. Zolnierkiewicz ◽  
P. Berczynski ◽  
A. Guskos ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin Wave ◽  
Sample Surface ◽  
Wave Mode ◽  
Austenite Phase ◽  
Magnetic Field Direction ◽  
Stiffness Constant ◽  
Out Of Plane ◽  
Different Temperatures ◽  
Expanded Austenite

AbstractFour samples of austenite coatings deposited by reactive magnetron sputtering on silicon substrate at four different temperatures and pressures were investigated by ferromagnetic resonance (FMR) method at room temperature. The expanded austenite phase S (γ N) layers with thickness in the 160–273 nm range and concentration of magnetic atoms: 72 % Fe, 18 % Cr and 10 % Ni, were obtained. The coatings with nanometric size grains were strongly textured and grown mostly in [100] direction, perpendicular to the sample surface. Intense FMR spectra were recorded at various angles between the static magnetic field direction and the sample surface. A strong magnetic anisotropy of the main uniform FMR mode was observed and the effective magnetization 4πM eff determined. Spin wave resonance (SWR) modes were observed in all investigated samples in out-of-plane geometry of the magnetic field. The resonance fields of SWR modes in our samples varied linearly with the spin wave mode number. The value of the effective magnon stiffness constant was determined assuming a parabolic shape of the magnetization variation across the sample thickness.

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