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Sharifabad ME, Soucaille R, Wang X, Rotherham M, Loughran T, Everett J, Cabrera D, Yang Y, Hicken R, Telling N. Optical Microscopy Using the Faraday Effect Reveals in Situ Magnetization Dynamics of Magnetic Nanoparticles in Biological Samples. ACS NANO 2024. [PMID: 38315113 PMCID: PMC10883041 DOI: 10.1021/acsnano.3c08955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
The study of exogenous and endogenous nanoscale magnetic material in biology is important for developing biomedical nanotechnology as well as for understanding fundamental biological processes such as iron metabolism and biomineralization. Here, we exploit the magneto-optical Faraday effect to probe intracellular magnetic properties and perform magnetic imaging, revealing the location-specific magnetization dynamics of exogenous magnetic nanoparticles within cells. The opportunities enabled by this method are shown in the context of magnetic hyperthermia; an effect where local heating is generated in magnetic nanoparticles exposed to high-frequency AC magnetic fields. Magnetic hyperthermia has the potential to be used as a cellular-level thermotherapy for cancer, as well as for other biomedical applications that target heat-sensitive cellular function. However, previous experiments have suggested that the cellular environment modifies the magnetization dynamics of nanoparticles, thus dramatically altering their heating efficiency. By combining magneto-optical and fluorescence measurements, we demonstrate a form of biological microscopy that we used here to study the magnetization dynamics of nanoparticles in situ, in both histological samples and living cancer cells. Correlative magnetic and fluorescence imaging identified aggregated magnetic nanoparticles colocalized with cellular lysosomes. Nanoparticles aggregated within these lysosomes displayed reduced AC magnetic coercivity compared to the same particles measured in an aqueous suspension or aggregated in other areas of the cells. Such measurements reveal the power of this approach, enabling investigations of how cellular location, nanoparticle aggregation, and interparticle magnetic interactions affect the magnetization dynamics and consequently the heating response of nanoparticles in the biological milieu.
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Affiliation(s)
- Maneea Eizadi Sharifabad
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
| | - Rémy Soucaille
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
| | - Xuyiling Wang
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
| | - Michael Rotherham
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
- Healthcare Technologies Institute, School of Chemical Engineering, University of Birmingham, Heritage Building, Mindelsohn Way, Edgbaston, Birmingham B15 2TH, United Kingdom
| | - Tom Loughran
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
| | - James Everett
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
| | - David Cabrera
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
| | - Ying Yang
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
| | - Robert Hicken
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
| | - Neil Telling
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent ST4 7QB, United Kingdom
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2
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Magnetic Functionalization of Scanning Probes by Focused Electron Beam Induced Deposition Technology. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7100140] [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
The fabrication of nanostructures with high resolution and precise control of the deposition site makes Focused Electron Beam Induced Deposition (FEBID) a unique nanolithography process. In the case of magnetic materials, apart from the FEBID potential in standard substrates for multiple applications in data storage and logic, the use of this technology for the growth of nanomagnets on different types of scanning probes opens new paths in magnetic sensing, becoming a benchmark for magnetic functionalization. This work reviews the recent advances in the integration of FEBID magnetic nanostructures onto cantilevers to produce advanced magnetic sensing devices with unprecedented performance.
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3
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Skyrmion Formation in Nanodisks Using Magnetic Force Microscopy Tip. NANOMATERIALS 2021; 11:nano11102627. [PMID: 34685062 PMCID: PMC8538463 DOI: 10.3390/nano11102627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/13/2021] [Accepted: 09/28/2021] [Indexed: 01/19/2023]
Abstract
We demonstrated numerically the skyrmion formation in ultrathin nanodisks using a magnetic force microscopy tip. We found that the local magnetic field generated by the magnetic tip significantly affects the magnetization state of the nanodisks and leads to the formation of skyrmions. Experimentally, we confirmed the influence of the local field on the magnetization states of the disks. Micromagnetic simulations explain the evolution of the magnetic state during magnetic force microscopy scanning and confirm the possibility of skyrmion formation. The formation of the horseshoe magnetic domain is a key transition from random labyrinth domain states into the skyrmion state. We showed that the formation of skyrmions by the magnetic probe is a reliable and repetitive procedure. Our findings provide a simple solution for skyrmion formation in nanodisks.
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Stenning KD, Gartside JC, Dion T, Vanstone A, Arroo DM, Branford WR. Magnonic Bending, Phase Shifting and Interferometry in a 2D Reconfigurable Nanodisk Crystal. ACS NANO 2021; 15:674-685. [PMID: 33320533 DOI: 10.1021/acsnano.0c06894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strongly interacting nanomagnetic systems are pivotal across next-generation technologies including reconfigurable magnonics and neuromorphic computation. Controlling magnetization states and local coupling between neighboring nanoelements allows vast reconfigurability and a host of associated functionalities. However, existing designs typically suffer from an inability to tailor interelement coupling post-fabrication and nanoelements restricted to a pair of Ising-like magnetization states. Here, we propose a class of reconfigurable magnonic crystals incorporating nanodisks as the functional element. Ferromagnetic nanodisks are crucially bistable in macrospin and vortex states, allowing interelement coupling to be selectively activated (macrospin) or deactivated (vortex). Through microstate engineering, we leverage the distinct coupling behaviors and magnonic band structures of bistable nanodisks to achieve reprogrammable magnonic waveguiding, bending, gating, and phase-shifting across a 2D network. The potential of nanodisk-based magnonics for wave-based computation is demonstrated via an all-magnon interferometer exhibiting XNOR logic functionality. Local microstate control is achieved here via topological magnetic writing using a magnetic force microscope tip.
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Affiliation(s)
- Kilian D Stenning
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jack C Gartside
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Troy Dion
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Alexander Vanstone
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daan M Arroo
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Will R Branford
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
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5
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Dobrovolskiy OV, Bunyaev SA, Vovk NR, Navas D, Gruszecki P, Krawczyk M, Sachser R, Huth M, Chumak AV, Guslienko KY, Kakazei GN. Spin-wave spectroscopy of individual ferromagnetic nanodisks. NANOSCALE 2020; 12:21207-21217. [PMID: 33057527 DOI: 10.1039/d0nr07015g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The increasing demand for nanoscale magnetic devices requires development of 3D magnetic nanostructures. In this regard, focused electron beam induced deposition (FEBID) is a technique of choice for direct-writing of complex nano-architectures with applications in nanomagnetism, magnon spintronics, and superconducting electronics. However, intrinsic properties of nanomagnets are often poorly known and can hardly be assessed by local optical probe techniques. Here, an original spatially resolved approach is demonstrated for spin-wave spectroscopy of individual circular magnetic elements with sample volumes down to about 10-3 μm3. The key component of the setup is a coplanar waveguide whose microsized central part is placed over a movable substrate with well-separated CoFe-FEBID nanodisks which exhibit standing spin-wave resonances. The circular symmetry of the disks allows for the deduction of the saturation magnetization and the exchange stiffness of the material using an analytical theory. A good correspondence between the results of analytical calculations and micromagnetic simulations is revealed, indicating a validity of the used analytical model going beyond the initial thin-disk approximation used in the theoretical derivation. The presented approach is especially valuable for the characterization of direct-write magnetic elements opening new horizons for 3D nanomagnetism and magnonics.
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Affiliation(s)
| | - Sergey A Bunyaev
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP)/Departamento de Física e Astronomia, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal
| | - Nikolay R Vovk
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP)/Departamento de Física e Astronomia, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal and Department of Physics, V. N. Karazin Kharkiv National University, Svobody Sq. 4, Kharkiv 61022, Ukraine
| | - David Navas
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP)/Departamento de Física e Astronomia, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal and Instituto de Ciencia de Materiales de Madrid, ICMM-CSIC, 28049 Madrid, Spain
| | - Pawel Gruszecki
- Faculty of Physics, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego St. 2, 61-614 Poznań, Poland and Institute of Molecular Physics, Polish Academy of Sciences, Mariana Smoluchowskiego St. 17, 60-179 Poznań, Poland
| | - Maciej Krawczyk
- Faculty of Physics, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego St. 2, 61-614 Poznań, Poland
| | - Roland Sachser
- Institute of Physics, Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Michael Huth
- Institute of Physics, Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Andrii V Chumak
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
| | - Konstantin Y Guslienko
- Division de Fisica de Materiales, Depto. Polimeros y Materiales Avanzados: Fisica, Quimica y Tecnologia, Universidad del Pais Vasco, UPV/EHU, Paseo M. Lardizabal 3, 20018 San Sebastian, Spain and IKERBASQUE, the Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
| | - Gleb N Kakazei
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP)/Departamento de Física e Astronomia, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal
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6
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Fernández-Pacheco A, Skoric L, De Teresa JM, Pablo-Navarro J, Huth M, Dobrovolskiy OV. Writing 3D Nanomagnets Using Focused Electron Beams. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3774. [PMID: 32859076 PMCID: PMC7503546 DOI: 10.3390/ma13173774] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/10/2020] [Accepted: 08/20/2020] [Indexed: 12/18/2022]
Abstract
Focused electron beam induced deposition (FEBID) is a direct-write nanofabrication technique able to pattern three-dimensional magnetic nanostructures at resolutions comparable to the characteristic magnetic length scales. FEBID is thus a powerful tool for 3D nanomagnetism which enables unique fundamental studies involving complex 3D geometries, as well as nano-prototyping and specialized applications compatible with low throughputs. In this focused review, we discuss recent developments of this technique for applications in 3D nanomagnetism, namely the substantial progress on FEBID computational methods, and new routes followed to tune the magnetic properties of ferromagnetic FEBID materials. We also review a selection of recent works involving FEBID 3D nanostructures in areas such as scanning probe microscopy sensing, magnetic frustration phenomena, curvilinear magnetism, magnonics and fluxonics, offering a wide perspective of the important role FEBID is likely to have in the coming years in the study of new phenomena involving 3D magnetic nanostructures.
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Affiliation(s)
- Amalio Fernández-Pacheco
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK;
| | - Luka Skoric
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK;
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA) and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
| | - Javier Pablo-Navarro
- Laboratorio de Microscopías Avanzadas (LMA) and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Michael Huth
- Institute of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany;
| | - Oleksandr V. Dobrovolskiy
- Institute of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany;
- Faculty of Physics, University of Vienna, 1090 Vienna, Austria
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7
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Plank H, Winkler R, Schwalb CH, Hütner J, Fowlkes JD, Rack PD, Utke I, Huth M. Focused Electron Beam-Based 3D Nanoprinting for Scanning Probe Microscopy: A Review. MICROMACHINES 2019; 11:E48. [PMID: 31906005 PMCID: PMC7019982 DOI: 10.3390/mi11010048] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 11/17/2022]
Abstract
Scanning probe microscopy (SPM) has become an essential surface characterization technique in research and development. By concept, SPM performance crucially depends on the quality of the nano-probe element, in particular, the apex radius. Now, with the development of advanced SPM modes beyond morphology mapping, new challenges have emerged regarding the design, morphology, function, and reliability of nano-probes. To tackle these challenges, versatile fabrication methods for precise nano-fabrication are needed. Aside from well-established technologies for SPM nano-probe fabrication, focused electron beam-induced deposition (FEBID) has become increasingly relevant in recent years, with the demonstration of controlled 3D nanoscale deposition and tailored deposit chemistry. Moreover, FEBID is compatible with practically any given surface morphology. In this review article, we introduce the technology, with a focus on the most relevant demands (shapes, feature size, materials and functionalities, substrate demands, and scalability), discuss the opportunities and challenges, and rationalize how those can be useful for advanced SPM applications. As will be shown, FEBID is an ideal tool for fabrication / modification and rapid prototyping of SPM-tipswith the potential to scale up industrially relevant manufacturing.
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Affiliation(s)
- Harald Plank
- Christian Doppler Laboratory for Direct–Write Fabrication of 3D Nano–Probes (DEFINE), Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria;
- Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria
- Graz Centre for Electron Microscopy, 8010 Graz, Austria
| | - Robert Winkler
- Christian Doppler Laboratory for Direct–Write Fabrication of 3D Nano–Probes (DEFINE), Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria;
| | | | - Johanna Hütner
- GETec Microscopy GmbH, 1220 Vienna, Austria; (C.H.S.); (J.H.)
| | - Jason D. Fowlkes
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (J.D.F.); (P.D.R.)
- Materials Science and Engineering, The University of Tennessee, Knoxville, Knoxville, TN 37996, USA
| | - Philip D. Rack
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (J.D.F.); (P.D.R.)
- Materials Science and Engineering, The University of Tennessee, Knoxville, Knoxville, TN 37996, USA
| | - Ivo Utke
- Mechanics of Materials and Nanostructures Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, 3602 Thun, Switzerland;
| | - Michael Huth
- Physics Institute, Goethe University Frankfurt, 60323 Frankfurt am Main, Germany;
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8
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Sanz-Martín C, Magén C, De Teresa JM. High Volume-Per-Dose and Low Resistivity of Cobalt Nanowires Grown by Ga + Focused Ion Beam Induced Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E1715. [PMID: 31805735 PMCID: PMC6955673 DOI: 10.3390/nano9121715] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 11/16/2022]
Abstract
The growth of ferromagnetic nanostructures by means of focused-Ga+-beam-induced deposition (Ga+-FIBID) using the Co2(CO)8 precursor has been systematically investigated. The work aimed to obtain growth conditions allowing for the simultaneous occurrence of high growth speed, good lateral resolution, low electrical resistivity, and ferromagnetic behavior. As a first result, it has been found that the competition between deposition and milling that is produced by the Ga+ beam is a limiting factor. In our working conditions, with the maximum available precursor flux, the maximum deposit thickness has been found to be 65 nm. The obtained volumetric growth rate is at least 50 times higher than in the case of deposition by focused-electron-beam-induced deposition. The lateral resolution of the deposits can be as good as 50 nm while using Ga+-beam currents lower than 10 pA. The high metallic content of the as-grown deposits gives rise to a low electrical resistivity, within the range 20-40 µΩ·cm. Magnetic measurements confirm the ferromagnetic nature of the deposits at room temperature. In conclusion, the set of obtained results indicates that the growth of functional ferromagnetic nanostructures by Ga+-FIBID while using the Co2(CO)8 precursor is a viable and competitive technique when compared to related nanofabrication techniques.
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Affiliation(s)
- Carlos Sanz-Martín
- Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain; (C.S.-M.); (C.M.)
| | - César Magén
- Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain; (C.S.-M.); (C.M.)
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - José María De Teresa
- Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain; (C.S.-M.); (C.M.)
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
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9
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Fernández-Pacheco A, Streubel R, Fruchart O, Hertel R, Fischer P, Cowburn RP. Three-dimensional nanomagnetism. Nat Commun 2017; 8:15756. [PMID: 28598416 PMCID: PMC5494189 DOI: 10.1038/ncomms15756] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/20/2017] [Indexed: 01/18/2023] Open
Abstract
Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications. Nanoscale magnetic devices play a key role in modern technologies but current applications involve only 2D structures like magnetic discs. Here the authors review recent progress in the fabrication and understanding of 3D magnetic nanostructures, enabling more diverse functionalities.
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Affiliation(s)
| | - Robert Streubel
- Division of Materials Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Olivier Fruchart
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, INAC, SPINTEC, F-38000 Grenoble, France
| | - Riccardo Hertel
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Department of Magnetic Objects on the Nanoscale, F-67000 Strasbourg, France
| | - Peter Fischer
- Division of Materials Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, UC Santa Cruz, Santa Cruz, California 95064, USA
| | - Russell P Cowburn
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
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10
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Sangiao S, Magén C, Mofakhami D, de Loubens G, De Teresa JM. Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2106-2115. [PMID: 29090112 PMCID: PMC5647723 DOI: 10.3762/bjnano.8.210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/12/2017] [Indexed: 05/05/2023]
Abstract
In this work, we present a detailed investigation of the magnetic properties of cobalt nanospheres grown on cantilever tips by focused electron beam induced deposition (FEBID). The cantilevers are extremely soft and the cobalt nanospheres are optimized for magnetic resonance force microscopy (MRFM) experiments, which implies that the cobalt nanospheres must be as small as possible while bearing high saturation magnetization. It was found that the cobalt content and the corresponding saturation magnetization of the nanospheres decrease for nanosphere diameters less than 300 nm. Electron holography measurements show the formation of a magnetic vortex state in remanence, which nicely agrees with magnetic hysteresis loops performed by local magnetometry showing negligible remanent magnetization. As investigated by local magnetometry, optimal behavior for high-resolution MRFM has been found for cobalt nanospheres with a diameter of ≈200 nm, which present atomic cobalt content of ≈83 atom % and saturation magnetization of 106 A/m, around 70% of the bulk value. These results represent the first comprehensive investigation of the magnetic properties of cobalt nanospheres grown by FEBID for application in MRFM.
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Affiliation(s)
- Soraya Sangiao
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - César Magén
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Fundación ARAID, 50018 Zaragoza, Spain
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Darius Mofakhami
- Service de Physique de l’Etat Condensé, CEA, CNRS, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - Grégoire de Loubens
- Service de Physique de l’Etat Condensé, CEA, CNRS, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - José María De Teresa
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC, Universidad de Zaragoza, 50009 Zaragoza, Spain
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11
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Tartakovskaya EV, Pardavi-Horvath M, McMichael RD. Spin wave localization in tangentially magnetized films. PHYSICAL REVIEW. B 2016; 93:214436. [PMID: 27551693 PMCID: PMC4990788 DOI: 10.1103/physrevb.93.214436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present an analytical description of localized spin wave modes that form in a parabolic field minimum in a thin ferromagnetic film. Mode profiles proportional to Hermite functions are eigenfuctions of the applied field and exchange parts of the equations of motion, and also provide a basis for numerical approximation of magnetostatic interactions. We find that the spin wave modes are roughly equally spaced in frequency and have roughly equal coupling to a uniform driving field. The calculated mode frequencies and corresponding profiles of localized spin wave modes are in good agreement with micromagnetic modeling and previously published experimental results on multiple resonances from a series of localized modes detected by ferromagnetic resonance force microscopy.
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Affiliation(s)
- Elena V. Tartakovskaya
- Institute of Magnetism NAS of Ukraine, Vernadsky Blvd 36b, 03142 Kiev, Ukraine
- Institute of High Technologies, Taras Shevchenko National University of Kiev, 03022 Kiev, Ukraine
| | - Martha Pardavi-Horvath
- School of Engineering and Applied Science, The George Washington University Washington, D.C. 20052, USA
| | - Robert D. McMichael
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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12
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Bunyaev SA, Golub VO, Salyuk OY, Tartakovskaya EV, Santos NM, Timopheev AA, Sobolev NA, Serga AA, Chumak AV, Hillebrands B, Kakazei GN. Splitting of standing spin-wave modes in circular submicron ferromagnetic dot under axial symmetry violation. Sci Rep 2015; 5:18480. [PMID: 26690826 PMCID: PMC4686882 DOI: 10.1038/srep18480] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/17/2015] [Indexed: 11/30/2022] Open
Abstract
The spin wave dynamics in patterned magnetic nanostructures is under intensive study during the last two decades. On the one hand, this interest is generated by new physics that can be explored in such structures. On the other hand, with the development of nanolithography, patterned nanoelements and their arrays can be used in many practical applications (magnetic recording systems both as media and read-write heads, magnetic random access memory, and spin-torque oscillators just to name a few). In the present work the evolution of spin wave spectra of an array of non-interacting Permalloy submicron circular dots for the case of magnetic field deviation from the normal to the array plane have been studied by ferromagnetic resonance technique. It is shown that such symmetry violation leads to a splitting of spin-wave modes, and that the number of the split peaks depends on the mode number. A quantitative description of the observed spectra is given using a perturbation theory for small angles of field inclination from the symmetry direction. The obtained results give possibility to predict transformation of spin wave spectra depending on direction of the external magnetic field that can be important for spintronic and nanomagnetic applications.
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Affiliation(s)
- S A Bunyaev
- IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física, Universidade do Porto, 4169-007 Porto, Portugal
| | - V O Golub
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - O Yu Salyuk
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - E V Tartakovskaya
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - N M Santos
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - A A Timopheev
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - N A Sobolev
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal.,National University of Science and Technology "MISiS", 119049 Moscow, Russia
| | - A A Serga
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - A V Chumak
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - G N Kakazei
- IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física, Universidade do Porto, 4169-007 Porto, Portugal
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13
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Losby JE, Sani FF, Grandmont DT, Diao Z, Belov M, Burgess JAJ, Compton SR, Hiebert WK, Vick D, Mohammad K, Salimi E, Bridges GE, Thomson DJ, Freeman MR. Torque-mixing magnetic resonance spectroscopy. Science 2015; 350:798-801. [DOI: 10.1126/science.aad2449] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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14
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Nanometre-scale probing of spin waves using single-electron spins. Nat Commun 2015; 6:7886. [PMID: 26249673 PMCID: PMC4918315 DOI: 10.1038/ncomms8886] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 06/23/2015] [Indexed: 11/15/2022] Open
Abstract
Pushing the frontiers of condensed-matter magnetism requires the development of tools that provide real-space, few-nanometre-scale probing of correlated-electron magnetic excitations under ambient conditions. Here we present a practical approach to meet this challenge, using magnetometry based on single nitrogen-vacancy centres in diamond. We focus on spin-wave excitations in a ferromagnetic microdisc, and demonstrate local, quantitative and phase-sensitive detection of the spin-wave magnetic field at ∼50 nm from the disc. We map the magnetic-field dependence of spin-wave excitations by detecting the associated local reduction in the disc's longitudinal magnetization. In addition, we characterize the spin–noise spectrum by nitrogen-vacancy spin relaxometry, finding excellent agreement with a general analytical description of the stray fields produced by spin–spin correlations in a 2D magnetic system. These complementary measurement modalities pave the way towards imaging the local excitations of systems such as ferromagnets and antiferromagnets, skyrmions, atomically assembled quantum magnets, and spin ice. Exploring magnetic excitations and spin textures on the nanoscale may lead to new spintronic technologies and new understanding of condensed matter. Here, the authors demonstrate the potential of single-electron spins in diamond to image such excitations by characterizing spin waves in a ferromagnetic microdisc.
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