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Bran C, Berganza E, Fernandez-Roldan JA, Palmero EM, Meier J, Calle E, Jaafar M, Foerster M, Aballe L, Fraile Rodriguez A, P Del Real R, Asenjo A, Chubykalo-Fesenko O, Vazquez M. Magnetization Ratchet in Cylindrical Nanowires. ACS NANO 2018; 12:5932-5939. [PMID: 29812903 DOI: 10.1021/acsnano.8b02153] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The unidirectional motion of information carriers such as domain walls in magnetic nanostrips is a key feature for many future spintronic applications based on shift registers. This magnetic ratchet effect has so far been achieved in a limited number of complex nanomagnetic structures, for example, by lithographically engineered pinning sites. Here we report on a simple remagnetization ratchet originated in the asymmetric potential from the designed increasing lengths of magnetostatically coupled ferromagnetic segments in FeCo/Cu cylindrical nanowires. The magnetization reversal in neighboring segments propagates sequentially in steps starting from the shorter segments, irrespective of the applied field direction. This natural and efficient ratchet offers alternatives for the design of three-dimensional advanced storage and logic devices.
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Affiliation(s)
- Cristina Bran
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Eider Berganza
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | | | - Ester M Palmero
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Jessica Meier
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Esther Calle
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Miriam Jaafar
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Michael Foerster
- ALBA Synchrotron Light Facility, CELLS , 08290 Barcelona , Spain
| | - Lucia Aballe
- ALBA Synchrotron Light Facility, CELLS , 08290 Barcelona , Spain
| | | | - Rafael P Del Real
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Agustina Asenjo
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | | | - Manuel Vazquez
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
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2
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Dutta S, Siddiqui SA, Currivan-Incorvia JA, Ross CA, Baldo MA. The Spatial Resolution Limit for an Individual Domain Wall in Magnetic Nanowires. NANO LETTERS 2017; 17:5869-5874. [PMID: 28813156 DOI: 10.1021/acs.nanolett.7b03199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Magnetic nanowires are the foundation of several promising nonvolatile computing devices, most notably magnetic racetrack memory and domain wall logic. Here, we determine the analog information capacity in these technologies, analyzing a magnetic nanowire containing a single domain wall. Although wires can be deliberately patterned with notches to define discrete positions for domain walls, the line edge roughness of the wire can also trap domain walls at dimensions below the resolution of the fabrication process, determining the fundamental resolution limit for the placement of a domain wall. Using a fractal model for the edge roughness, we show theoretically and experimentally that the analog information capacity for wires is limited by the self-affine statistics of the wire edge roughness, a relevant result for domain wall devices scaled to regimes where edge roughness dominates the energy landscape in which the walls move.
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3
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Zhang J, Agramunt-Puig S, Del-Valle N, Navau C, Baró MD, Estradé S, Peiró F, Pané S, Nelson BJ, Sanchez A, Nogués J, Pellicer E, Sort J. Tailoring Staircase-like Hysteresis Loops in Electrodeposited Trisegmented Magnetic Nanowires: a Strategy toward Minimization of Interwire Interactions. ACS APPLIED MATERIALS & INTERFACES 2016; 8:4109-4117. [PMID: 26804742 DOI: 10.1021/acsami.5b11747] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A new strategy to minimize magnetic interactions between nanowires (NWs) dispersed in a fluid is proposed. Such a strategy consists of preparing trisegmented NWs containing two antiparallel ferromagnetic segments with dissimilar coercivity separated by a nonmagnetic spacer. The trisegmented NWs exhibit a staircase-like hysteresis loop with tunable shape that depends on the relative length of the soft- and hard-magnetic segments and the respective values of saturation magnetization. Such NWs are prepared by electrodepositing CoPt/Cu/Ni in a polycarbonate (PC) membrane. The antiparallel alignment is set by applying suitable magnetic fields while the NWs are still embedded in the PC membrane. Analytic calculations are used to demonstrate that the interaction magnetic energy from fully compensated trisegmented NWs with antiparallel alignment is reduced compared to a single-component NW with the same length or the trisegmented NWs with the two ferromagnetic counterparts parallel to each other. The proposed approach is appealing for the use of magnetic NWs in certain biological or catalytic applications where the aggregation of NWs is detrimental for optimized performance.
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Affiliation(s)
- Jin Zhang
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Sebastià Agramunt-Puig
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Núria Del-Valle
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Carles Navau
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Maria D Baró
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Sònia Estradé
- LENS, MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain
| | - Francesca Peiró
- LENS, MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain
| | - Salvador Pané
- Institute of Robotics & Intelligent Systems (IRIS), ETH Zürich , CH-8092 Zurich, Switzerland
| | - Bradley J Nelson
- Institute of Robotics & Intelligent Systems (IRIS), ETH Zürich , CH-8092 Zurich, Switzerland
| | - Alvaro Sanchez
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Josep Nogués
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) , Barcelona, Catalonia, Spain
| | - Eva Pellicer
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
| | - Jordi Sort
- Departament de Fı́sica, Universitat Autònoma de Barcelona , Bellaterra, E-08193 Barcelona, Catalonia, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) , Barcelona, Catalonia, Spain
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4
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Dobrovolskiy OV, Kompaniiets M, Sachser R, Porrati F, Gspan C, Plank H, Huth M. Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1082-90. [PMID: 26171284 PMCID: PMC4464159 DOI: 10.3762/bjnano.6.109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/31/2015] [Indexed: 05/25/2023]
Abstract
Controlling magnetic properties on the nanometer-scale is essential for basic research in micro-magnetism and spin-dependent transport, as well as for various applications such as magnetic recording, imaging and sensing. This has been accomplished to a very high degree by means of layered heterostructures in the vertical dimension. Here we present a complementary approach that allows for a controlled tuning of the magnetic properties of Co/Pt heterostructures on the lateral mesoscale. By means of in situ post-processing of Pt- and Co-based nano-stripes prepared by focused electron beam induced deposition (FEBID) we are able to locally tune their coercive field and remanent magnetization. Whereas single Co-FEBID nano-stripes show no hysteresis, we find hard-magnetic behavior for post-processed Co/Pt nano-stripes with coercive fields up to 850 Oe. We attribute the observed effects to the locally controlled formation of the CoPt L10 phase, whose presence has been revealed by transmission electron microscopy.
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Affiliation(s)
- Oleksandr V Dobrovolskiy
- Physikalisches Institut, Goethe University, 60438 Frankfurt am Main, Germany
- Physics Department, V. Karazin Kharkiv National University, 61077 Kharkiv, Ukraine
| | - Maksym Kompaniiets
- Physikalisches Institut, Goethe University, 60438 Frankfurt am Main, Germany
| | - Roland Sachser
- Physikalisches Institut, Goethe University, 60438 Frankfurt am Main, Germany
| | - Fabrizio Porrati
- Physikalisches Institut, Goethe University, 60438 Frankfurt am Main, Germany
| | | | - Harald Plank
- Graz Centre for Electron Microscopy, 8010 Graz, Austria
- Institute for Electron Microscopy and Nanoanalysis, TU Graz, 8010 Graz, Austria
| | - Michael Huth
- Physikalisches Institut, Goethe University, 60438 Frankfurt am Main, Germany
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Vogt K, Fradin F, Pearson J, Sebastian T, Bader S, Hillebrands B, Hoffmann A, Schultheiss H. Realization of a spin-wave multiplexer. Nat Commun 2014; 5:3727. [DOI: 10.1038/ncomms4727] [Citation(s) in RCA: 273] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/26/2014] [Indexed: 11/09/2022] Open
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O'Brien L, Beguivin A, Petit D, Fernandez-Pacheco A, Read D, Cowburn RP. Domain wall interactions at a cross-shaped vertex. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:5794-5805. [PMID: 23166381 DOI: 10.1098/rsta.2012.0089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The interaction of two domain walls (DWs) at a cross-shaped vertex fabricated from two ferromagnetic nanowires has been experimentally investigated. Both magnetostatically repulsive and attractive interactions have been probed. It is found that in the repulsive case, a passing DW may directly induce the depinning of another that is already pinned at a vertex. This effect can be qualitatively described by considering only simple, magnetostatic-charge-based arguments. In the attractive case, however, asymmetric pinning is found, with complete suppression of depinning possible. This observed effect is contrary to simple charge-based arguments and highlights the need for full micromagnetic characterization of the DW interactions in more complex systems.
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Affiliation(s)
- L O'Brien
- Thin Film Magnetism Group, Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, UK.
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Franken JH, Swagten HJM, Koopmans B. Shift registers based on magnetic domain wall ratchets with perpendicular anisotropy. NATURE NANOTECHNOLOGY 2012; 7:499-503. [PMID: 22796743 DOI: 10.1038/nnano.2012.111] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/01/2012] [Indexed: 06/01/2023]
Abstract
The movement of magnetic domain walls can be used to build a device known as a shift register, which has applications in memory and logic circuits. However, the application of magnetic domain wall shift registers has been hindered by geometrical restrictions, by randomness in domain wall displacement and by the need for high current densities or rotating magnetic fields. Here, we propose a new approach in which the energy landscape experienced by the domain walls is engineered to favour a unidirectional ratchet-like propagation. The domain walls are defined between domains with an out-of-plane (perpendicular) magnetization, which allows us to route domain walls along arbitrary in-plane paths using a time-varying applied magnetic field with fixed orientation. In addition, this ratchet-like motion causes the domain walls to lock to discrete positions along these paths, which is useful for digital devices. As a proof-of-principle experiment we demonstrate the continuous propagation of two domain walls along a closed-loop path in a platinum/cobalt/platinum strip.
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Affiliation(s)
- J H Franken
- Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.
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O'Brien L, Lewis ER, Fernández-Pacheco A, Petit D, Cowburn RP, Sampaio J, Read DE. Dynamic oscillations of coupled domain walls. PHYSICAL REVIEW LETTERS 2012; 108:187202. [PMID: 22681110 DOI: 10.1103/physrevlett.108.187202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Indexed: 06/01/2023]
Abstract
In domain wall (DW) excitation experiments, nonlinearity (NL) intrinsic to the DW dynamics is often hard to distinguish from perturbation due to the confining potential or DW distortion. Here we numerically investigate the dynamic oscillations of magnetostatically coupled DWs: a system well understood in the quasistatic limit. NL is observed, even for a harmonic potential, due to the intrinsic DW motion. This behavior is principally dependent on terms normally associated with the DW canonical momentum and is in contrast with a NL restoring potential. This NL is not observable in quasistatic measurements, relatively insensitive to the confining potential, and may be tuned by the nanowire parameters. The shown NLs are present in any DW restoring potential and must be accounted for when probing DW potential landscapes.
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Affiliation(s)
- L O'Brien
- Thin Film Magnetism Group, Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom.
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Vázquez M, Basheed GA, Infante G, Del Real RP. Trapping and injecting single domain walls in magnetic wire by local fields. PHYSICAL REVIEW LETTERS 2012; 108:037201. [PMID: 22400777 DOI: 10.1103/physrevlett.108.037201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Indexed: 05/31/2023]
Abstract
A single domain wall (DW) moves at linearly increasing velocity under an increasing homogeneous drive magnetic field. Present experiments show that the DW is braked and finally trapped at a given position when an additional antiparallel local magnetic field is applied. That position and its velocity are further controlled by suitable tuning of the local field. In turn, the parallel local field of small amplitude does not significantly affect the effective wall speed at long distance, although it generates tail-to-tail and head-to-head pairs of walls moving along opposite directions when that field is strong enough.
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Affiliation(s)
- Manuel Vázquez
- Materials Science Institute of Madrid, CSIC, 28049 Madrid, Spain.
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