Time domain magnetization dynamics study to estimate interlayer exchange coupling constant in Nd-Fe-B/Ni80Fe20 films

Mandal, Ruma; Ogawa, Daisuke; Yukiya, Tamazawa; Ishioka, Kunie; Shima, T.; Kato, Takeshi; Iwata, S.; Takahashi, Y. K.; Hirosawa, S.; Hono, K.

doi:10.1016/j.jmmm.2018.08.010

Cited by 11 publications

(8 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…S2 in SM [23]), and f R was estimated by the median of the spectrum of Ī(f ) [25]. The estimated f R at 400 K (T /T c ∼ 0.5) in the present simulation is 141 GHz under zero field and then f R = 197 GHz un-der 2T field, which is the same order of the experimental value (161GHz) at room temperature [8].…”

supporting

confidence: 60%

“…The change of the precession frequency accompanying a SR transition has been detected recently in a rare-earth orthoferrite (RFeO 3 ) by using time-resolved magnetooptical effect microscope [5][6][7]. Very recently a TDM of spin dynamics has been performed to evaluate the interlayer exchange coupling between hard and soft Nd magnet layers, and the resonance frequency for a single thick layer of the hard Nd magnet was estimated to be f = ω/(2π) = 161 GHz under an external field at 2 T at room temperature [8]. The SR transition in the Nd magnet is a new target for TDM.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Nontrivial temperature dependence of ferromagnetic resonance frequency for spin reorientation transitions

Nishino

Miyashita

2019

Phys. Rev. B

View full text Add to dashboard Cite

We find unusual temperature dependence of the ferromagnetic resonance (FMR) frequency fR for the spin-reorientation (SR) transition, in which the easy axis changes depending on temperature, observed in the Nd permanent magnet, Nd2Fe14B: fR ∼ 0 below the SR transition temperature (TR), drastic increase of fR around TR, and decrease from a peak at higher temperatures. It is nontrivial that the SR transition causes the unusual behavior of the FMR frequency in a wide temperature region. We show the mechanism of the temperature dependence by theoretical and computational analyses. We derive a general relation between fR and magnetizations to help the understanding of the mechanism, and clarify that the fluctuation of the transverse magnetization is a key ingredient for the resonance in all temperature regions.

show abstract

supporting

confidence: 60%

mentioning

confidence: 99%

Nontrivial temperature dependence of ferromagnetic resonance frequency for spin reorientation transitions

Nishino

Miyashita

2019

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Magnetic hysteresis loops were measured at RT using a vibrating sample magnetometer (VSM) with in-plane and out-of-plane geometry. The ultrafast magnetization dynamic measurements were carried out by an all-optical TRMOKE microscope. − A high power mode-locked Yb:KGW laser (PHAROS, Light Conversion) with a wavelength of 1028 nm, a pulse width of 290 fs, and a repetition rate of 10 kHz was used as a pump beam to excite the magnetization dynamics of the sample. The second harmonic (λ = 515 nm) of the fundamental laser beam was used as a probe to measure the magneto-optical Kerr rotation as a function of the time delay between the pump and probe beams with the help of the optical bridge detector and the lock-in-amplifier in a phase-sensitive manner.…”

Section: Experimental Detailsmentioning

confidence: 99%

Nanoscale-Thick Ni-Based Half-Heusler Alloys with Structural Ordering-Dependent Ultralow Magnetic Damping: Implications for Spintronic Applications

Mandal

Kurniawan

Suzuki

et al. 2022

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Atomic ordering and its consequence on the crystal structure are fundamental issues in the application of half-metallic Heusler alloys considered as a high spin-polarized electron source. NiMnSb is a promising half-metallic half-Heusler alloy for spintronic devices due to its low magnetic damping, noncentrosymmetric crystal structure, and rich anisotropies. Here, we report a highquality half-metallic epitaxial nano-scale thick NiMnSb alloy film grown on a Cr/ Ag-buffered MgO (001) single crystalline substrate. High temperature deposition is a crucial parameter for crystal growth and magneto-dynamic properties such as damping, anisotropy, magnetization, etc. After investigating the ferromagnetic resonance (FMR) spectroscopy using a time-resolved magneto-optical Kerr (TRMOKE) microscope and calculating the crystal structure using VESTA and the density of states from first-principles calculations, we discuss how the deposition temperature influences the crystal ordering, damping, and magnetization. Ultralow Gilbert damping with high anisotropic field and saturation magnetization were found for the highly ordered C1 b structured nanoscale thick NiMnSb film deposited at 573 K. We also found quite nice agreement between theoretical and experimental data of crystal ordering and damping that explains how the ordering affects the magnetic parameter as well as sample quality. Furthermore, the negative anisotropic magnetoresistance ratio implies the robust bulk half-metallicity. Such unique combination of highly ordered half-metallic NiMnSb alloy in the nano-scale regime with ultralow damping can be regarded as an advantage for applications in spintronic devices.

show abstract

“…Since the directions of M 1 and M 2 are aligned parallelly with the external field and change little with the field strength, there is a nearly linear field dependence of the frequencies for both the HF and LF modes at sufficiently high fields. The dependence of f vs H ext can be well described by a theoretical model which considers the coupling strength between two layers. , The exchange field ( H ex ) can be extracted from the model fitting of frequency data in the high-field region . To date, the damping studies using TR-MOKE for PMA-SAF structures are still limited in scope, and only the effective damping constant has been reported in the literature. , A comprehensive model for separating the intrinsic α from the inhomogeneous broadening contribution is still missing and needs further development.…”

Section: Representative Examplesmentioning

confidence: 99%

“…The dependence of f vs H ext can be well described by a theoretical model which considers the coupling strength between two layers. 59,60 The exchange field (H ex ) can be extracted from the model fitting of frequency data in the highfield region. 61 To date, the damping studies using TR-MOKE for PMA-SAF structures are still limited in scope, and only the effective damping constant has been reported in the literature.…”

Section: Representative Examplesmentioning

confidence: 99%

Materials Engineering Enabled by Time-Resolved Magneto-Optical Kerr Effect for Spintronic Applications

Huang

Lattery

Wang

2020

ACS Appl. Electron. Mater.

View full text Add to dashboard Cite

As an updated version of the ultrafast pump–probe laser technique, the time-resolved magneto-optical Kerr effect (TR-MOKE) methodology enables the detection of magnetization dynamics with superb temporal (sub-picosecond) and spatial (diffraction-limited beam spot) resolutions. It is a powerful tool to characterize material properties and to reveal the rich physics of magnetization dynamics in magnetic thin films, which serve as the essential building blocks for spintronic and magnetic recording devices. In this spotlight article, we will highlight the recent advances in the development of TR-MOKE metrology and its applications for capturing the magnetization dynamics in technologically important spintronic materials. We cover several representative examples based on research activities carried out at the University of Minnesota (UMN), including studies of Gilbert damping, spin-strain coupling, and interlayer exchange coupling of perpendicular magnetic materials. A brief discussion will be also presented, which highlights several other emerging research topics that are potentially enabled by this metrology to form a more comprehensive picture of its applications for emerging materials and technologies.

show abstract

Time domain magnetization dynamics study to estimate interlayer exchange coupling constant in Nd-Fe-B/Ni80Fe20 films

Cited by 11 publications

References 26 publications

Nontrivial temperature dependence of ferromagnetic resonance frequency for spin reorientation transitions

Nontrivial temperature dependence of ferromagnetic resonance frequency for spin reorientation transitions

Nanoscale-Thick Ni-Based Half-Heusler Alloys with Structural Ordering-Dependent Ultralow Magnetic Damping: Implications for Spintronic Applications

Materials Engineering Enabled by Time-Resolved Magneto-Optical Kerr Effect for Spintronic Applications

Contact Info

Product

Resources

About