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Kee JY, Kim KT, Lee IH, Seo I, Chang JY, Lee AY, Noh WS, Chang YJ, Park SY, Choe SB, Kim DH, Kim KW, Choi Y, Lee DR, Choi JW. Additive roles of antiferromagnetically coupled elements in the magnetic proximity effect in the GdFeCo/Pt system. Sci Rep 2024; 14:9476. [PMID: 38658634 PMCID: PMC11043343 DOI: 10.1038/s41598-024-60076-9] [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: 12/19/2023] [Accepted: 04/18/2024] [Indexed: 04/26/2024] Open
Abstract
Interfacial magnetic interactions between different elements are the origin of various spin-transport phenomena in multi-elemental magnetic systems. We investigate the coupling between the magnetic moments of the rare-earth, transition-metal, and heavy-metal elements across the interface in a GdFeCo/Pt thin film, an archetype system to investigate ferrimagnetic spintronics. The Pt magnetic moments induced by the antiferromagnetically aligned FeCo and Gd moments are measured using element-resolved x-ray measurements. It is revealed that the proximity-induced Pt magnetic moments are always aligned parallel to the FeCo magnetic moments, even below the ferrimagnetic compensation temperature where FeCo has a smaller moment than Gd. This is understood by a theoretical model showing distinct effects of the rare-earth Gd 4f and transition-metal FeCo 3d magnetic moments on the Pt electronic states. In particular, the Gd and FeCo work in-phase to align the Pt moment in the same direction, despite their antiferromagnetic configuration. The unexpected additive roles of the two antiferromagnetically coupled elements exemplify the importance of detailed interactions among the constituent elements in understanding magnetic and spintronic properties of thin film systems.
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Affiliation(s)
- Jung Yun Kee
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
- Department of Physics, Soongsil University, Seoul, 06978, Korea
| | - Kook Tae Kim
- Department of Physics, Soongsil University, Seoul, 06978, Korea
| | - In Hak Lee
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
| | - Ilwan Seo
- Department of Physics, Soongsil University, Seoul, 06978, Korea
| | - Jun-Young Chang
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
| | - Ah-Yeon Lee
- Center for Research Equipment, Division of Scientific Instrumentation & Management, Korea Basic Science Institute (KBSI), Daejeon, 34133, Korea
| | - Woo-Suk Noh
- Korea Foundation for Max Planck POSTECH/Korea Research Initiative, Pohang, 37673, Korea
| | - Young Jun Chang
- Department of Physics, University of Seoul, Seoul, 02504, Korea
| | - Seung-Young Park
- Center for Scientific Instrumentation, Division of Scientific Instrumentation & Management, Korea Basic Science Institute (KBSI), Daejeon, 34133, Korea
| | - Sug-Bong Choe
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
| | - Duck-Ho Kim
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea.
- Department of Physics, Yonsei University, Seoul, 03722, Korea.
| | - Yongseong Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.
| | - Dong Ryeol Lee
- Department of Physics, Soongsil University, Seoul, 06978, Korea.
| | - Jun Woo Choi
- Center for Spintronics, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea.
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Cho J, Jung J, Kim SB, Ju WR, Kim DH, Byun M, Kim JS. The Stack Optimization of Magnetic Heterojunction Structures for Next-Generation Spintronic Logic Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6418. [PMID: 37834555 PMCID: PMC10573172 DOI: 10.3390/ma16196418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/18/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
Magnetic heterojunction structures with a suppressed interfacial Dzyaloshinskii-Moriya interaction and a sustainable long-range interlayer exchange coupling are achieved with an ultrathin platinum insertion layer. The systematic inelastic light scattering spectroscopy measurements indicate that the insertion layer restores the symmetry of the system and, then, the interfacial Dzyaloshinskii-Moriya interaction, which can prevent the identical magnetic domain wall motions, is obviously minimized. Nevertheless, the strong interlayer exchange coupling of the system is maintained. Consequently, synthetic ferromagnetic and antiferromagnetic exchange couplings as a function of the ruthenium layer thickness are observed as well. Therefore, these optimized magnetic multilayer stacks can avoid crucial issues, such as domain wall tilting and position problems, for next-generation spintronic logic applications. Moreover, the synthetic antiferromagnetic coupling can open a new path to develop a radically different NOT gate via current-induced magnetic domain wall motions and inversions.
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Affiliation(s)
- Jaehun Cho
- Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Jinyong Jung
- Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Seong Bok Kim
- Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Woo Ri Ju
- Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Da Hyeon Kim
- Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
- Department of Materials Engineering, Keimyung University, Daegu 42601, Republic of Korea
| | - Myunghwan Byun
- Department of Materials Engineering, Keimyung University, Daegu 42601, Republic of Korea
| | - June-Seo Kim
- Division of Nanotechnology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
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Verna A, Alippi P, Offi F, Barucca G, Varvaro G, Agostinelli E, Albrecht M, Rutkowski B, Ruocco A, Paoloni D, Valvidares M, Laureti S. Disclosing the Nature of Asymmetric Interface Magnetism in Co/Pt Multilayers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:12766-12776. [PMID: 35254812 DOI: 10.1021/acsami.1c22341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nowadays, a wide number of applications based on magnetic materials rely on the properties arising at the interface between different layers in complex heterostructures engineered at the nanoscale. In ferromagnetic/heavy metal multilayers, such as the [Co/Pt]N and [Co/Pd]N systems, the magnetic proximity effect was demonstrated to be asymmetric, thus inducing a magnetic moment on the Pt (Pd) layer that is typically higher at the top Co/Pt(Pd) interface. In this work, advanced spectroscopic and imaging techniques were combined with theoretical approaches to clarify the origin of this asymmetry both in Co/Pt trilayers and, for the first time, in multilayer systems that are more relevant for practical applications. The different magnetic moment induced at the Co/Pt interfaces was correlated to the microstructural features that are in turn affected by the growth processes that induce a different intermixing during the film deposition, thus influencing the interface magnetic profile.
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Affiliation(s)
- Adriano Verna
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, Roma I-00146, Italy
- ENEA-FSN-Fiss-SNI, Casaccia R. C., Via Anguillarese 301, Roma 00123, Italy
| | - Paola Alippi
- Istituto di Struttura della Materia, CNR, Monterotondo Scalo, Roma 00015, Italy
| | - Francesco Offi
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, Roma I-00146, Italy
| | - Gianni Barucca
- Dipartimento SIMAU, Università Politecnica Delle Marche, Via Brecce Bianche, Ancona 60121, Italy
| | - Gaspare Varvaro
- Istituto di Struttura della Materia, CNR, nM2-Lab, Monterotondo Scalo, Roma 00015, Italy
| | - Elisabetta Agostinelli
- Istituto di Struttura della Materia, CNR, nM2-Lab, Monterotondo Scalo, Roma 00015, Italy
| | - Manfred Albrecht
- Institute of Physics, University of Augsburg, Universitätsstraße 1 Nord, Augsburg D-86159, Germany
| | - Bogdan Rutkowski
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. A. Mickiewicza 30, Kraków 30-059, Poland
| | - Alessandro Ruocco
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, Roma I-00146, Italy
| | - Daniele Paoloni
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, Roma I-00146, Italy
| | - Manuel Valvidares
- ALBA Synchrotron Light Source, Cerdanyola del Vallès, Barcelona E-08290, Spain
| | - Sara Laureti
- Istituto di Struttura della Materia, CNR, nM2-Lab, Monterotondo Scalo, Roma 00015, Italy
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Magneto-Electronic Hydrogen Gas Sensors: A Critical Review. CHEMOSENSORS 2022. [DOI: 10.3390/chemosensors10020049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Devices enabling early detection of low concentrations of leaking hydrogen and precision measurements in a wide range of hydrogen concentrations in hydrogen storage systems are essential for the mass-production of fuel-cell vehicles and, more broadly, for the transition to the hydrogen economy. Whereas several competing sensor technologies are potentially suitable for this role, ultra-low fire-hazard, contactless and technically simple magneto-electronic sensors stand apart because they have been able to detect the presence of hydrogen gas in a range of hydrogen concentrations from 0.06% to 100% at atmospheric pressure with the response time approaching the industry gold standard of one second. This new kind of hydrogen sensors is the subject of this review article, where we inform academic physics, chemistry, material science and engineering communities as well as industry researchers about the recent developments in the field of magneto-electronic hydrogen sensors, including those based on magneto-optical Kerr effect, anomalous Hall effect and Ferromagnetic Resonance with a special focus on Ferromagnetic Resonance (FMR)-based devices. In particular, we present the physical foundations of magneto-electronic hydrogen sensors and we critically overview their advantages and disadvantages for applications in the vital areas of the safety of hydrogen-powered cars and hydrogen fuelling stations as well as hydrogen concentration meters, including those operating directly inside hydrogen-fuelled fuel cells. We believe that this review will be of interest to a broad readership, also facilitating the translation of research results into policy and practice.
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Resonant Soft X-ray Reflectivity in the Study of Magnetic Properties of Low-Dimensional Systems. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7100136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this review, the technique of resonant soft X-ray reflectivity in the study of magnetic low-dimensional systems is discussed. This technique is particularly appealing in the study of magnetization at buried interfaces and to discriminate single elemental contributions to magnetism, even when this is ascribed to few atoms. The major fields of application are described, including magnetic proximity effects, thin films of transition metals and related oxides, and exchange-bias systems. The fundamental theoretical background leading to dichroism effects in reflectivity is also briefly outlined.
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Won YC, Lim SH. Interfacial properties of [Pt/Co/Pt] trilayers probed through magnetometry. Sci Rep 2021; 11:10779. [PMID: 34031523 PMCID: PMC8144629 DOI: 10.1038/s41598-021-90239-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/10/2021] [Indexed: 11/16/2022] Open
Abstract
The magnetic and interface properties of [Pt/Co/Pt] were investigated. First, the magnetic properties were determined from the magnetic dead layer plots, in which the Co layer was considered as two distinct parts representing different magnetic properties. The two parts with low and high tCo ranges are close to and away from the top interface (Co/Pt), respectively. The part close to the top interface shows a smaller magnetization (M) value and nonlinear behavior. However, the other part shows a higher M value closer to the bulk value and a linear behavior. The nonlinear behavior of the M values of the low tCo range was converted to an impurity level using simple assumptions. The results showed the effect of the top Pt layer on the magnetic properties of the Co layer. The results clearly demonstrate that magnetometry could be utilized as a means to understand the interface quality of magnetic multilayer systems.
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Affiliation(s)
- Young Chan Won
- Department of Nano Semiconductor Engineering, Korea University, Seoul, 02841, South Korea
| | - Sang Ho Lim
- Department of Nano Semiconductor Engineering, Korea University, Seoul, 02841, South Korea. .,Department of Materials Science and Engineering, Korea University, Seoul, 02841, South Korea.
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Pandey E, Singh BB, Sharangi P, Bedanta S. Strain engineered domain structure and their relaxation in perpendicularly magnetized Co/Pt deposited on flexible polyimide. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/ab90cb] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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Garlow JA, Pollard SD, Beleggia M, Dutta T, Yang H, Zhu Y. Quantification of Mixed Bloch-Néel Topological Spin Textures Stabilized by the Dzyaloshinskii-Moriya Interaction in Co/Pd Multilayers. PHYSICAL REVIEW LETTERS 2019; 122:237201. [PMID: 31298899 DOI: 10.1103/physrevlett.122.237201] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/02/2019] [Indexed: 06/10/2023]
Abstract
The three-dimensional structure of nanoscale topological spin textures stabilized by the Dzyaloshinskii-Moriya interaction is governed by the delicate competition between the exchange, demagnetization, and anisotropy energies. The quantification of such spin textures through direct experimental methods is crucial towards understanding the fundamental physics associated with their ordering, as well as their manipulation in spintronic devices. Here, we extend the Lorentz transmission electron microscopy technique to quantify mixed Bloch-Néel chiral spin textures stabilized by the Dzyaloshinskii-Moriya interaction in Co/Pd multilayers. Analysis of the observed intensities under varied imaging conditions coupled to corroborative micromagnetic simulations yields vital parameters that dictate the stability and properties of the complex spin texture, namely, the degree of mixed Bloch-Néel character, the domain wall width, the strength of the Dzyaloshinskii-Moriya interaction, and the exchange stiffness. This approach provides the necessary framework for the application of quantitative Lorentz phase microscopy to a broad array of topological spin systems.
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Affiliation(s)
- Joseph A Garlow
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, USA
| | - Shawn D Pollard
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Marco Beleggia
- DTU Nanolab, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Tanmay Dutta
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, USA
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Brandão J, Dugato DA, Seeger RL, Denardin JC, Mori TJA, Cezar JC. Observation of magnetic skyrmions in unpatterned symmetric multilayers at room temperature and zero magnetic field. Sci Rep 2019; 9:4144. [PMID: 30858450 PMCID: PMC6412027 DOI: 10.1038/s41598-019-40705-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 02/08/2019] [Indexed: 11/10/2022] Open
Abstract
Magnetic skyrmions are promising candidates for the next generation of spintronic devices due to their small size and topologically protected structure. One challenge for using these magnetic states in applications lies on controlling the nucleation process and stabilization that usually requires an external force. Here, we report on the evidence of skyrmions in unpatterned symmetric Pd/Co/Pd multilayers at room temperature without prior application of neither electric current nor magnetic field. Decreasing the ferromagnetic interlayer thickness, the tuning of the physical properties across the ferromagnetic/non-magnetic interface gives rise to a transition from worm like domains patterns to isolated skyrmions as demonstrated by magnetic force microscopy. On the direct comparison of the measured and simulated skyrmions size, the interfacial Dzyaloshinskii-Moriya interaction (iDMI) was estimated, reveling that isolated skyrmions are just stabilized at zero magnetic field taking into account non-null values of iDMI. Our findings provide new insights towards the use of stabilized skyrmions for room temperature devices in nominally symmetric multilayers.
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Affiliation(s)
- J Brandão
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970, Campinas, SP, Brazil.
| | - D A Dugato
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970, Campinas, SP, Brazil.,Departamento de Física, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil
| | - R L Seeger
- Departamento de Física, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil
| | - J C Denardin
- Departamento de Física, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil.,Departamento de Física and CEDENNA, Universidad de Santiago de Chile, 9170124, Santiago, Chile
| | - T J A Mori
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970, Campinas, SP, Brazil
| | - J C Cezar
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970, Campinas, SP, Brazil.
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The interfacial nature of proximity-induced magnetism and the Dzyaloshinskii-Moriya interaction at the Pt/Co interface. Sci Rep 2017; 7:16835. [PMID: 29203797 PMCID: PMC5715054 DOI: 10.1038/s41598-017-17137-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/22/2017] [Indexed: 11/08/2022] Open
Abstract
The Dzyaloshinskii-Moriya interaction has been shown to stabilise Nèel domain walls in magnetic thin films, allowing high domain wall velocities driven by spin current effects. The interfacial Dzyaloshinskii-Moriya interaction (IDMI) occurs at the interface between ferromagnetic and heavy metal layers with strong spin-orbit coupling, but details of the interaction remain to be understood and the role of proximity induced magnetism (PIM) in the heavy metal is unknown. Here IDMI and PIM are reported in Pt determined as a function of Au and Ir spacer layers in Pt/Co/Au,Ir/Pt. Both interactions are found to be sensitive to sub-nanometre changes in the spacer thickness, correlating over sub-monolayer spacer thicknesses, but not for thicker spacers where IDMI continues to change even after PIM is lost.
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