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Ishii Y, Yamasaki Y, Kozuka Y, Lustikova J, Nii Y, Onose Y, Yokoyama Y, Mizumaki M, Adachi JI, Nakao H, Arima TH, Wakabayashi Y. Microscopic evaluation of spin and orbital moment in ferromagnetic resonance. Sci Rep 2024; 14:15504. [PMID: 38969719 PMCID: PMC11226459 DOI: 10.1038/s41598-024-66139-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 06/27/2024] [Indexed: 07/07/2024] Open
Abstract
Time-resolved X-ray magnetic circular dichroism under the effects of ferromagnetic resonance (FMR), known as X-ray ferromagnetic resonance (XFMR) measurements, enables direct detection of precession dynamics of magnetic moment. Here we demonstrated XFMR measurements and Bayesian analyses as a quantitative probe for the precession of spin and orbital magnetic moments under the FMR effect. Magnetization precessions in two different Pt/Ni-Fe thin film samples were directly detected. Furthermore, the ratio of dynamical spin and orbital magnetic moments was evaluated quantitatively by Bayesian analyses for XFMR energy spectra around the Ni L 2 , 3 absorption edges. Our study paves the way for a microscopic investigation of the contribution of the orbital magnetic moment to magnetization dynamics.
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Affiliation(s)
- Yuta Ishii
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan.
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Japan.
| | - Yuichi Yamasaki
- National Institute for Materials Science (NIMS), Tsukuba, 305-0047, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Yusuke Kozuka
- National Institute for Materials Science (NIMS), Tsukuba, 305-0047, Japan
| | - Jana Lustikova
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, 980-8577, Japan
| | - Yoichi Nii
- Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Yoshinori Onose
- Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Yuichi Yokoyama
- Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, 679-5198, Japan
| | - Masaichiro Mizumaki
- Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, 679-5198, Japan
- Faculty of Science, Course for Physical Sciences, Kumamoto University, Kumamoto, 860-0862, Japan
| | - Jun-Ichi Adachi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Hironori Nakao
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
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Burn DM, Lin JC, Fujita R, Achinuq B, Bibby J, Singh A, Frisk A, van der Laan G, Hesjedal T. Spin pumping through nanocrystalline topological insulators. NANOTECHNOLOGY 2023; 34:275001. [PMID: 36947871 DOI: 10.1088/1361-6528/acc663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
The topological surface states (TSSs) in topological insulators (TIs) offer exciting prospects for dissipationless spin transport. Common spin-based devices, such as spin valves, rely on trilayer structures in which a non-magnetic layer is sandwiched between two ferromagnetic (FM) layers. The major disadvantage of using high-quality single-crystalline TI films in this context is that a single pair of spin-momentum locked channels spans across the entire film, meaning that only a very small spin current can be pumped from one FM to the other, along the side walls of the film. On the other hand, using nanocrystalline TI films, in which the grains are large enough to avoid hybridization of the TSSs, will effectively increase the number of spin channels available for spin pumping. Here, we used an element-selective, x-ray based ferromagnetic resonance technique to demonstrate spin pumping from a FM layer at resonance through the TI layer and into the FM spin sink.
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Affiliation(s)
- David M Burn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Jheng-Cyuan Lin
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Ryuji Fujita
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Barat Achinuq
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Joshua Bibby
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Angadjit Singh
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Andreas Frisk
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Thorsten Hesjedal
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
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Burn DM, Zhang S, Zhai K, Chai Y, Sun Y, van der Laan G, Hesjedal T. Mode-Resolved Detection of Magnetization Dynamics Using X-ray Diffractive Ferromagnetic Resonance. NANO LETTERS 2020; 20:345-352. [PMID: 31855436 DOI: 10.1021/acs.nanolett.9b03989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Collective spin excitations of ordered magnetic structures offer great potential for the development of novel spintronic devices. The present approach relies on micromagnetic models to explain the origins of dynamic modes observed by ferromagnetic resonance (FMR) studies, since experimental tools to directly reveal the origins of the complex dynamic behavior are lacking. Here we demonstrate a new approach which combines resonant magnetic X-ray diffraction with FMR, thereby allowing for a reconstruction of the real-space spin dynamics of the system. This new diffractive FMR technique builds on X-ray detected FMR that allows for element-selective dynamic studies, giving unique access to specific wave components of static and dynamic coupling in magnetic heterostructures. In combination with diffraction, FMR is elevated to the level of a modal spectroscopy technique, potentially opening new pathways for the development of spintronic devices.
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Affiliation(s)
- David M Burn
- Magnetic Spectroscopy Group , Diamond Light Source , Didcot OX11 0DE , United Kingdom
| | - Shilei Zhang
- School of Physical Science and Technology , ShanghaiTech University , Shanghai , 201210 , China
- ShanghaiTech Laboratory for Topological Physics , ShanghaiTech University , Shanghai 200031 , China
| | - Kun Zhai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- School of Physical Science , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Yisheng Chai
- Low Temperature Physics Laboratory, College of Physics, and Center of Quantum Materials and Devices , Chongqing University , Chongqing 401331 , China
| | - Young Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- School of Physical Science , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Gerrit van der Laan
- Magnetic Spectroscopy Group , Diamond Light Source , Didcot OX11 0DE , United Kingdom
| | - Thorsten Hesjedal
- Clarendon Laboratory, Department of Physics , University of Oxford , Parks Road , Oxford OX1 3PU , United Kingdom
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Bonetti S. X-ray imaging of spin currents and magnetisation dynamics at the nanoscale. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:133004. [PMID: 28096523 DOI: 10.1088/1361-648x/aa5a13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding how spins move in time and space is the aim of both fundamental and applied research in modern magnetism. Over the past three decades, research in this field has led to technological advances that have had a major impact on our society, while improving the understanding of the fundamentals of spin physics. However, important questions still remain unanswered, because it is experimentally challenging to directly observe spins and their motion with a combined high spatial and temporal resolution. In this article, we present an overview of the recent advances in x-ray microscopy that allow researchers to directly watch spins move in time and space at the microscopically relevant scales. We discuss scanning x-ray transmission microscopy (STXM) at resonant soft x-ray edges, which is available at most modern synchrotron light sources. This technique measures magnetic contrast through the x-ray magnetic circular dichroism (XMCD) effect at the resonant absorption edges, while focusing the x-ray radiation at the nanometre scale, and using the intrinsic pulsed structure of synchrotron-generated x-rays to create time-resolved images of magnetism at the nanoscale. In particular, we discuss how the presence of spin currents can be detected by imaging spin accumulation, and how the magnetisation dynamics in thin ferromagnetic films can be directly imaged. We discuss how a direct look at the phenomena allows for a deeper understanding of the the physics at play, that is not accessible to other, more indirect techniques. Finally, we present an overview of the exciting opportunities that lie ahead to further understand the fundamentals of novel spin physics, opportunities offered by the appearance of diffraction limited storage rings and free electron lasers.
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Affiliation(s)
- Stefano Bonetti
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
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Bonetti S, Kukreja R, Chen Z, Spoddig D, Ollefs K, Schöppner C, Meckenstock R, Ney A, Pinto J, Houanche R, Frisch J, Stöhr J, Dürr HA, Ohldag H. Microwave soft x-ray microscopy for nanoscale magnetization dynamics in the 5-10 GHz frequency range. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:093703. [PMID: 26429444 DOI: 10.1063/1.4930007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/21/2015] [Indexed: 06/05/2023]
Abstract
We present a scanning transmission x-ray microscopy setup combined with a novel microwave synchronization scheme for studying high frequency magnetization dynamics at synchrotron light sources. The sensitivity necessary to detect small changes in the magnetization on short time scales and nanometer spatial dimensions is achieved by combining the excitation mechanism with single photon counting electronics that is locked to the synchrotron operation frequency. Our instrument is capable of creating direct images of dynamical phenomena in the 5-10 GHz range, with high spatial resolution. When used together with circularly polarized x-rays, the above capabilities can be combined to study magnetic phenomena at microwave frequencies, such as ferromagnetic resonance (FMR) and spin waves. We demonstrate the capabilities of our technique by presenting phase resolved images of a ∼6 GHz nanoscale spin wave generated by a spin torque oscillator, as well as the uniform ferromagnetic precession with ∼0.1° amplitude at ∼9 GHz in a micrometer-sized cobalt strip.
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Affiliation(s)
- Stefano Bonetti
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Roopali Kukreja
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Zhao Chen
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Detlef Spoddig
- Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
| | - Katharina Ollefs
- Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
| | - Christian Schöppner
- Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
| | - Ralf Meckenstock
- Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
| | - Andreas Ney
- Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
| | - Jude Pinto
- Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Richard Houanche
- Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Josef Frisch
- Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Joachim Stöhr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Hermann A Dürr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Hendrik Ohldag
- Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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Detection of microwave phase variation in nanometre-scale magnetic heterostructures. Nat Commun 2013; 4:2025. [DOI: 10.1038/ncomms3025] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/20/2013] [Indexed: 11/08/2022] Open
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Gopman DB, Liu H, Kent AD. A flux-coupled ac/dc magnetizing device. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:065101. [PMID: 23822372 DOI: 10.1063/1.4807696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance.
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Affiliation(s)
- D B Gopman
- Department of Physics, New York University, 4 Washington Place, New York, New York 10003, USA.
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Goulon J, Rogalev A, Goujon G, Wilhelm F, Ben Youssef J, Gros C, Barbe JM, Guilard R. X-ray detected magnetic resonance: a unique probe of the precession dynamics of orbital magnetization components. Int J Mol Sci 2012; 12:8797-835. [PMID: 22272105 PMCID: PMC3257102 DOI: 10.3390/ijms12128797] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/12/2011] [Accepted: 11/15/2011] [Indexed: 11/16/2022] Open
Abstract
X-ray Detected Magnetic Resonance (XDMR) is a novel spectroscopy in which X-ray Magnetic Circular Dichroism (XMCD) is used to probe the resonant precession of local magnetization components in a strong microwave pump field. We review the conceptual bases of XDMR and recast them in the general framework of the linear and nonlinear theories of ferromagnetic resonance (FMR). Emphasis is laid on the information content of XDMR spectra which offer a unique opportunity to disentangle the precession dynamics of spin and orbital magnetization components at given absorbing sites. For the sake of illustration, we focus on selected examples in which marked differences were found between FMR and XDMR spectra simultaneously recorded on ferrimagnetically ordered iron garnets. With pumping capabilities extended up to sub-THz frequencies, high-field XDMR should allow us to probe the precession of orbital magnetization components in paramagnetic organometallic complexes with large zero-field splitting. Even more challenging, we suggest that XDMR spectra might be recorded on selected antiferromagnetic crystals for which orbital magnetism is most often ignored in the absence of any supporting experimental evidence.
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Affiliation(s)
- Jośe Goulon
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France.
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Buschhorn S, Brüssing F, Abrudan R, Zabel H. Adaption of a diffractometer for time-resolved X-ray resonant magnetic scattering. JOURNAL OF SYNCHROTRON RADIATION 2011; 18:212-216. [PMID: 21335907 DOI: 10.1107/s0909049510045358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 11/04/2010] [Indexed: 05/30/2023]
Abstract
A new set-up is presented to measure element-selective magnetization dynamics using the ALICE chamber [Grabis et al. (2003), Rev. Sci. Instrum. 74, 4048-4051] at the BESSY II synchrotron at the Helmholtz-Zentrum Berlin. A magnetic-field pulse serves as excitation, and the magnetization precession is probed by element-selective X-ray resonant magnetic scattering. With the use of single-bunch-generated X-rays a temporal resolution well below 100 ps is reached. The ALICE diffractometer environment enables investigations of thin films, described here, multilayers and laterally structured samples in reflection or diffuse scattering geometry. The combination of the time-resolved set-up with a cryostat in the ALICE chamber will allow temperature-dependent studies of precessional magnetization dynamics and of damping constants to be conducted over a large temperature range and for a large variety of systems in reflection geometry.
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Affiliation(s)
- Stefan Buschhorn
- Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany.
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Boero G, Rusponi S, Kavich J, Rizzini AL, Piamonteze C, Nolting F, Tieg C, Thiele JU, Gambardella P. Longitudinal detection of ferromagnetic resonance using x-ray transmission measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:123902. [PMID: 20059149 DOI: 10.1063/1.3267192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We describe a setup for the x-ray detection of ferromagnetic resonance in the longitudinal geometry using element-specific transmission measurements. Thin magnetic film samples are placed in a static magnetic field collinear with the propagation direction of a polarized soft x-ray beam and driven to ferromagnetic resonance by a continuous wave microwave magnetic field perpendicular to it. The transmitted photon flux is measured both as a function of the x-ray photon energy and as a function of the applied static magnetic field. We report experiments performed on a 15 nm film of doped Permalloy (Ni(73)Fe(18)Gd(7)Co(2)) at the L(3)/L(2)-edges of Fe, Co, and Ni. The achieved ferromagnetic resonance sensitivity is about 0.1 monolayers/square root(Hz). The obtained results are interpreted in the framework of a conductivity tensor based formalism. The factors limiting the sensitivity as well as different approaches for the x-ray detection of ferromagnetic resonance are discussed.
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Affiliation(s)
- G Boero
- Ecole Polytechninque Federale de Lausanne, CH-1015 Lausanne, Switzerland.
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