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Guo Y, Bai L. Dissipative Particle Dynamics Simulation for the Self-Assembly of Symmetric Pentablock Terpolymers Melts under 1D Confinements. Polymers (Basel) 2023; 15:3982. [PMID: 37836033 PMCID: PMC10575399 DOI: 10.3390/polym15193982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/30/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
The phase behavior of CBABC pentablock terpolymers confined in thin films is investigated using the Dissipative Particle Dynamic method. Phase diagrams are constructed and used to reveal how chain length (i-block length), block composition and wall selectivity influence the self-assembly structures. Under neutral walls, four categories of morphologies, i.e., perpendicular lamellae, core-shell types of microstructures, complex networks, and half-domain morphologies, are identified with the change in i-block length. Ordered structures are more common at weak polymer-polymer interaction strengths. For polymers of a consistent chain length, when one of the three components has a relatively smaller length, the morphologies transition is sensitive to block composition. With selective walls, parallel lamellae structures are prevalent. Wall selectivity also impacts chain conformations. While a large portion of chains form loop conformations under A-selective walls, more chains adopt bridge conformation when the wall prefers C-blocks. These findings offer insights for designing nanopatterns using symmetric pentablock terpolymers.
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Affiliation(s)
- Yingying Guo
- School of Science, Qingdao University of Technology, Qingdao 266525, China
| | - Linqing Bai
- School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao 266525, China;
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2
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Park SY, Jeong HU, Lee J, Jang J, Kim S, Choi C, Kim JU, Kim JK. Graphoepitaxy of Symmetric Six-Arm Star-Shaped Poly(methyl methacrylate)-block-Polystyrene Copolymer Thin Film. Macromol Rapid Commun 2021; 42:e2100411. [PMID: 34347926 DOI: 10.1002/marc.202100411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/28/2021] [Indexed: 11/06/2022]
Abstract
The authors perform directed self-assembly based on graphoepitaxy of symmetric six-arm star-shaped poly(methyl methacrylate)-block-polystyrene copolymer [(PMMA-b-PS)6 ] thin film. The affinity between each block and the trench wall is adjusted by using polymer brushes or selective gold (Au) deposition. When the surface of the trench is strongly selective for the PMMA block, (n+0.75)L0 thick (n is the number of the lamellae, L0 is lamellar domain spacing) lamellae parallel to the trench wall are formed at each side, while nanotubes are formed away from the trench wall. However, for a trench grafted with PS brushes, nanotubes are formed beside (n+0.25)L0 thick lamellar layers. By adjusting the trench width (W) and the affinity between the block and the wall, various dual nanopatterns consisting of lines and nanotubes are fabricated. Moreover, when the trench wall is selectively deposited by Au, asymmetric dual nanopattern is formed, where different numbers of lines exist on each side wall, while nanotubes are formed in the middle of the trench. The observed morphologies depending on the commensurability condition between W and L0 are consistent with predictions by self-consistent field theory.
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Affiliation(s)
- So Yeong Park
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hyeon U Jeong
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jaeyong Lee
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Junho Jang
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sanghoon Kim
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Chungryong Choi
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jaeup U Kim
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jin Kon Kim
- National Creative Research Initiative Center for Smart Block Copolymers, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
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3
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Gao H, Zhang T, Zhang Y, Chen Y, Liu B, Wu J, Liu X, Li Y, Peng M, Zhang Y, Xie G, Zhao F, Fan HM. Ellipsoidal magnetite nanoparticles: a new member of the magnetic-vortex nanoparticles family for efficient magnetic hyperthermia. J Mater Chem B 2021; 8:515-522. [PMID: 31840711 DOI: 10.1039/c9tb00998a] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The development of magnetic iron oxide nanoparticles with novel topological magnetic domain structures, such as the vortex-domain structure, is a promising strategy for improving the application performance of conventional superparamagnetic iron oxides while maintaining their good biocompatibility. Here, we fabricated a new kind of magnetic-vortex nanoparticles, i.e., ellipsoidal magnetite nanoparticles (EMPs), for cancer magnetic hyperthermia. The magnetization configurations and switching behaviours of the EMPs were analyzed by analytical simulations and Lorentz TEM, demonstrating the magnetic vortex structures of both single and coupled EMPs. The EMP treatment of 4T1 cells exposed to an alternating magnetic field (AMF) induced a significant decrease in the cell viability by ∼51.5%, which indicated a much higher cytotoxic effect in comparison with commercial superparamagnetic iron oxides (Resovist, ∼12.0%). In addition, the in vivo high efficacy of 4T1 breast tumor inhibition was also achieved by using EMP-mediated magnetic hyperthermia. Our results not only provide a new type of magnetic-vortex nanoparticles for efficient hyperthermia but also enrich the family of magnetic iron oxide nanoparticles for various biomedical applications.
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Affiliation(s)
- Hongxu Gao
- Science and Technology on Combustion and Explosion Laboratory, Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
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4
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Giordano MC, Baumgaertl K, Escobar Steinvall S, Gay J, Vuichard M, Fontcuberta I Morral A, Grundler D. Plasma-Enhanced Atomic Layer Deposition of Nickel Nanotubes with Low Resistivity and Coherent Magnetization Dynamics for 3D Spintronics. ACS Appl Mater Interfaces 2020; 12:40443-40452. [PMID: 32805802 DOI: 10.1021/acsami.0c06879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report plasma-enhanced atomic layer deposition (ALD) to prepare conformal nickel thin films and nanotubes using nickelocene as a precursor, water as the oxidant agent, and an in-cycle plasma-enhanced reduction step with hydrogen. The optimized ALD pulse sequence, combined with a post-processing annealing treatment, allowed us to prepare 30 nm-thick metallic Ni layers with a resistivity of 8 μΩ cm at room temperature and good conformality both on the planar substrates and nanotemplates. Thus, we fabricated several micrometers-long nickel nanotubes with diameters ranging from 120 to 330 nm. We report the correlation between ALD growth and functional properties of individual Ni nanotubes characterized in terms of magnetotransport and the confinement of spin-wave modes. The findings offer novel perspectives for Ni-based spintronics and magnonic devices operated in the GHz frequency regime with 3D device architectures.
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Affiliation(s)
| | | | - S Escobar Steinvall
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | | | | | - A Fontcuberta I Morral
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Institute of Physics, School of Basic Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - D Grundler
- Institute of Microengineering (IMT), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Brock L, Sheng J. Robust Fabrication of Polymeric Nanowire with Anodic Aluminum Oxide Templates. Micromachines (Basel) 2019; 11:E46. [PMID: 31905961 DOI: 10.3390/mi11010046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/24/2019] [Accepted: 12/27/2019] [Indexed: 11/16/2022]
Abstract
Functionalization of a surface with biomimetic nano-/micro-scale roughness (wires) has attracted significant interests in surface science and engineering as well as has inspired many real-world applications including anti-fouling and superhydrophobic surfaces. Although methods relying on lithography include soft-lithography greatly increase our abilities in structuring hard surfaces with engineered nano-/micro-topologies mimicking real-world counterparts, such as lotus leaves, rose petals, and gecko toe pads, scalable tools enabling us to pattern polymeric substrates with the same structures are largely absent in literature. Here we present a robust and simple technique combining anodic aluminum oxide (AAO) templating and vacuum-assisted molding to fabricate nanowires over polymeric substrates. We have demonstrated the efficacy and robustness of the technique by successfully fabricating nanowires with large aspect ratios (>25) using several common soft materials including both cross-linking polymers and thermal plastics. Furthermore, a model is also developed to determine the length and molding time based on nanowires material properties (e.g., viscosity and interfacial tension) and operational parameters (e.g., pressure, vacuum, and AAO template dimension). Applying the technique, we have further demonstrated the confinement effects on polymeric crosslinking processes and shown substantial lengthening of the curing time.
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Antoine S, Aissou K, Mumtaz M, Pécastaings G, Buffeteau T, Fleury G, Hadziioannou G. Nanoscale Archimedean Tilings Formed by 3‐Miktoarm Star Terpolymer Thin Films. Macromol Rapid Commun 2019; 40:e1800860. [DOI: 10.1002/marc.201800860] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/26/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Ségolène Antoine
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
| | - Karim Aissou
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
| | - Muhammad Mumtaz
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
| | - Gilles Pécastaings
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
| | - Thierry Buffeteau
- Institut des Sciences MoléculairesCNRS – Université Bordeaux 351 cours de la libération F‐33405 Talence Cedex France
| | - Guillaume Fleury
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
| | - Georges Hadziioannou
- Laboratoire de Chimie des Polymères OrganiquesCNRS – ENSCPB – Université de Bordeaux 16 Avenue Pey‐Berland F‐33607 Pessac Cedex France
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7
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Klein E, Heymann L, Hungria AB, Lesyuk R, Klinke C. Colloidal lead iodide nanorings. Nanoscale 2018; 10:21197-21208. [PMID: 30417187 PMCID: PMC6251342 DOI: 10.1039/c8nr06430j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/02/2018] [Indexed: 06/01/2023]
Abstract
Colloidal chemistry of nanomaterials experienced a tremendous development in the last decades. In the course of the journey 0D nanoparticles, 1D nanowires, and 2D nanosheets have been synthesized. They have in common to possess a simple topology. We present a colloidal synthesis strategy for lead iodide nanorings, with a non-trivial topology. First, two-dimensional structures were synthesized in nonanoic acid as the sole solvent. Subsequently, they underwent an etching process in the presence of trioctylphosphine, which determines the size of the hole in the ring structure. We propose a mechanism for the formation of lead iodide nanosheets which also explains the etching of the two-dimensional structures starting from the inside, leading to nanorings. In addition, we demonstrate a possible application of the as-prepared nanorings in photodetectors. These devices are characterized by a fast response, high gain values, and a linear relation between photocurrent and incident light power intensity over a large range. The synthesis approach allows for inexpensive large-scale production of nanorings with tunable properties.
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Affiliation(s)
- Eugen Klein
- Institute of Physical Chemistry
, University of Hamburg
,
Martin-Luther-King-Platz 6
, 20146 Hamburg
, Germany
.
| | - Leonard Heymann
- Institute of Physical Chemistry
, University of Hamburg
,
Martin-Luther-King-Platz 6
, 20146 Hamburg
, Germany
.
| | - Ana B. Hungria
- Universidad de Cádiz. Facultad de Ciencias
, Campus Rio San Pedro
,
Cadiz 11510
, Spain
| | - Rostyslav Lesyuk
- Institute of Physical Chemistry
, University of Hamburg
,
Martin-Luther-King-Platz 6
, 20146 Hamburg
, Germany
.
- Pidstryhach Institute for Applied Problems of Mechanics and Mathematics of NAS of Ukraine
,
Naukowa Str. 3b
, 79060 Lviv
, Ukraine
| | - Christian Klinke
- Institute of Physical Chemistry
, University of Hamburg
,
Martin-Luther-King-Platz 6
, 20146 Hamburg
, Germany
.
- Department of Chemistry
, Swansea University – Singleton Park
,
Swansea SA2 8PP
, UK
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8
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Salinas HD, Restrepo J, Iglesias Ò. Change in the magnetic configurations of tubular nanostructures by tuning dipolar interactions. Sci Rep 2018; 8:10275. [PMID: 29980728 PMCID: PMC6035215 DOI: 10.1038/s41598-018-28598-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/26/2018] [Indexed: 02/07/2023] Open
Abstract
We have investigated the equilibrium states of ferromagnetic single wall nanotubes by means of atomistic Monte Carlo simulations of a zig-zag lattice of Heisenberg spins on the surface of a cylinder. The main focus of our study is to determine how the competition between short-range exchange (J) and long-range dipolar (D) interactions influences the low temperature magnetic order of the nanotubes as well as the thermal-driven transitions involved. Apart from the uniform and vortex states occurring for dominant J or D, we find that helical states become stable for a range of intermediate values of γ = D/J that depends on the radius and length of the nanotube. Introducing a vorticity order parameter to better characterize helical and vortex states, we find the pseudo-critical temperatures for the transitions between these states and we establish the magnetic phase diagrams of their stability regions as a function of the nanotube aspect ratio. Comparison of the energy of the states obtained by simulation with those of simpler theoretical structures that interpolate continuously between them, reveals a high degree of metastability of the helical structures that might be relevant for their reversal modes.
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Affiliation(s)
- H D Salinas
- Grupo de Magnetismo y Simulación G+, Instituto de Física, Universidad de Antioquia. A.A., 1226, Medellín, Colombia
| | - J Restrepo
- Grupo de Magnetismo y Simulación G+, Instituto de Física, Universidad de Antioquia. A.A., 1226, Medellín, Colombia
| | - Òscar Iglesias
- Departament de Física de la Matèria Condensada and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, Av., Diagonal 647, 08028, Barcelona, Spain.
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9
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Chen AP, Gonzalez J, Guslienko K. Magnetization Reversal Modes in Short Nanotubes with Chiral Vortex Domain Walls. Materials (Basel) 2018; 11:ma11010101. [PMID: 29320455 PMCID: PMC5793599 DOI: 10.3390/ma11010101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/06/2018] [Accepted: 01/08/2018] [Indexed: 11/16/2022]
Abstract
Micromagnetic simulations of magnetization reversal were performed for magnetic nanotubes of a finite length, L, equal to 1 and 2 μm, 50 and 100 nm radii, R, and uniaxial anisotropy with “easy axis” parallel to the tube length. I.e., we considered relatively short nanotubes with the aspect ratio L/R in the range 10–40. The non-uniform curling magnetization states on both ends of the nanotubes can be treated as vortex domain walls (DW). The domain wall length, Lc, depends on the tube geometric parameters and the anisotropy constant Ku, and determines the magnetization reversal mode, as well as the switching field value. For nanotubes with relative small values of Lc (Lc/L < 0.2) the magnetization reversal process is characterized by flipping of the magnetization in the middle uniform state. Whereas, for relative large values of Lc, in the reverse magnetic field, coupling of two vortex domain walls with opposite magnetization rotation directions results in the formation of a specific narrow Néel type DW in the middle of the nanotube. The nanotube magnetization suddenly aligns to the applied field at the switching field, collapsing the central DW.
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Affiliation(s)
- Ai Ping Chen
- Department Materials Physics, Faculty of Chemistry, University of the Basque Country, UPV/EHU, 20018 San Sebastián, Spain.
| | - Julian Gonzalez
- Department Materials Physics, Faculty of Chemistry, University of the Basque Country, UPV/EHU, 20018 San Sebastián, Spain.
| | - Konstantin Guslienko
- Department Materials Physics, Faculty of Chemistry, University of the Basque Country, UPV/EHU, 20018 San Sebastián, Spain.
- IKERBASQUE, The Basque Foundation for Science, 48013 Bilbao, Spain.
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11
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Kim SS, Kang D, Sohn BH. Fabrication of size-controlled nanoring arrays by selective incorporation of ionic liquids in diblock copolymer micellar cores. Nanotechnology 2017; 28:225303. [PMID: 28443831 DOI: 10.1088/1361-6528/aa6f81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the synthesis of arrayed nanorings with tunable physical dimensions from thin films of polystyrene-block-poly(4-vinylpyridine) (PS-P4VP) micelles. For accurate control of the inner and outer diameters of the nanorings, we added imidazolium-based ionic liquids (ILs) into the micellar solution, which were eventually incorporated into the micellar cores. We observed the structural changes of the micellar cores coated on a substrate due to the presence of ILs. The spin-coated micellar cores were treated with an acidic precursor solution and generated toroid nanostructures, of which size depended on the amount of IL loaded into the micelles. We then treated the transformed micellar films with oxygen plasma to produce arrays of various metal and oxide nanorings on a substrate. The spacings and diameters of nanorings were governed by the molecular weight of the PS-P4VP and the amount of IL used. We also demonstrated that arrayed Pt nanorings enabled the fabrication of reduced graphene oxide anti-nanoring arrays via a catalytic tailoring process.
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12
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McKeever C, Ogrin FY, Aziz MM. Dynamic susceptibility of concentric permalloy rings with opposite chirality vortices. J Appl Phys 2017; 121:203901. [PMID: 28579634 PMCID: PMC5443686 DOI: 10.1063/1.4983759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/05/2017] [Indexed: 06/07/2023]
Abstract
The high frequency dynamic behaviour of concentric permalloy nanorings with vortex domain structures with a thickness of 20 nm, a width in the range of 100 nm-250 nm, and a separation in the range of 10 nm-600 nm is investigated by micromagnetic simulations. The aim is to explore the ferromagnetic resonance of the concentric ring structure as a function of geometric parameters of the system. The dynamic susceptibility spectrum and spatial localization of the ferromagnetic resonance mode are investigated for varying ring widths and separations. The frequency of oscillation is significantly impacted by the presence of the magnetostatic interaction between each ring and can be modulated by a variation in the ring width and separation. The spatial localization of the uniform mode is found to vary as a function of ring separation, which corresponds to a large variation in amplitude of the real and imaginary components of the dynamic susceptibility.
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Affiliation(s)
- C McKeever
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Devon EX4 4QL, United Kingdom
| | - F Y Ogrin
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Devon EX4 4QL, United Kingdom
| | - M M Aziz
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Devon EX4 4QL, United Kingdom
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13
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Aissou K, Mumtaz M, Marcasuzaa P, Brochon C, Cloutet E, Fleury G, Hadziioannou G. Highly Ordered Nanoring Arrays Formed by Templated Si-Containing Triblock Terpolymer Thin Films. Small 2017; 13:1603184. [PMID: 28092432 DOI: 10.1002/smll.201603184] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/09/2016] [Indexed: 05/21/2023]
Abstract
Laterally ordered nanorings with a periodicity of 38 nm are produced from the directed self-assembly of poly(1,1-dimethylsilacyclobutane)-block-polystyrene-block-poly(methyl methacrylate) thin films on topographically patterned substrates. Such nanoscale arrays with vertically oriented rings are highly desired in technological applications including memory using magnetic recording, metamaterial, waveguide, etc.
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Affiliation(s)
- Karim Aissou
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Muhammad Mumtaz
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Pierre Marcasuzaa
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Cyril Brochon
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Eric Cloutet
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Guillaume Fleury
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
| | - Georges Hadziioannou
- Laboratoire de Chimie des Polymères Organiques, CNRS-ENSCPB-Université de Bordeaux, 16 Avenue Pey-Berland, F-33607, Pessac Cedex, France
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14
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Komorowski PG, Cottam MG. Localization of the electronic excitations in single-walled carbon nanotubes with embedded line impurities. J Phys Condens Matter 2016; 28:035301. [PMID: 26705125 DOI: 10.1088/0953-8984/28/3/035301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A matrix operator formalism is used to study the excitations in long, single-walled carbon nanotubes with the dynamic electronic properties described by a tight-binding model where the interactions between atoms take place via nearest-neighbour hopping. Defects in the form of substitutional impurity atoms are introduced to study the localized electronic modes of the nanotube as well as the propagating modes of the pure (host) material. The impurities are assumed to have the form of one or more line defects parallel to the nanotube axis. Two geometric configurations are investigated corresponding to the longitudinal axis of the nanotube being parallel to either a zigzag or an armchair direction of the graphene lattice. A tridiagonal matrix technique is employed to solve the electronic operator equations that provide a description of the frequencies of the discrete modes of the system and their spatial amplitudes. Numerical examples are presented for different nanotube diameters and spatial configurations of the impurity lines.
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Affiliation(s)
- P G Komorowski
- Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7, Canada
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15
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Hilse M, Herfort J, Jenichen B, Trampert A, Hanke M, Schaaf P, Geelhaar L, Riechert H. GaAs-Fe₃Si core-shell nanowires: nanobar magnets. Nano Lett 2013; 13:6203-6209. [PMID: 24274677 DOI: 10.1021/nl4035994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Semiconductor-ferromagnet GaAs-Fe3Si core-shell nanowires were grown by molecular beam epitaxy and analyzed by scanning and transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, and magnetic force microscopy. We obtained closed and smooth Fe3Si shells with a crystalline structure that show ferromagnetic properties with magnetizations along the nanowire axis (perpendicular to the substrate). Such nanobar magnets are promising candidates to enable the fabrication of new forward-looking devices in the field of spintronics and magnetic recording.
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Affiliation(s)
- Maria Hilse
- Paul-Drude-Institut für Festkörperelektronik , Hausvogteiplatz 5-7, 10117 Berlin, Germany
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Lee SH, Yoon S, Jeong H, Han M, Choi SM, Kim JG, Park JW, Jung GY, Cho BK, Kim WB. Printable nanoscale metal ring arrays via vertically aligned carbon nanotube platforms. Nanoscale 2013; 5:10653-10659. [PMID: 24057061 DOI: 10.1039/c3nr02620e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper reports a novel and efficient strategy for fabricating sub-100 nm metal ring arrays using a simple printing process. Vertically aligned carbon nanotubes that are supported by hexagonally ordered channels of alumina matrices are used as a stamp to print nanoscale ring patterns, which is a very unique stamping platform that has never been reported. Using this strategy, uniform nanoring patterns of various metals can be directly printed onto a wide range of substrate surfaces under ambient conditions. Significantly, the size and interval of the printed nanorings can be systematically tuned by controlling the ring-shaped tip dimensions of the pristine stamps. An advanced example of these printable nanoscale metal ring arrays is explicitly embodied in this work by investigation of the plasmon resonances of metal nanorings with different sizes and intervals.
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Affiliation(s)
- Sang Ho Lee
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
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Halpern AR, Corn RM. Lithographically patterned electrodeposition of gold, silver, and nickel nanoring arrays with widely tunable near-infrared plasmonic resonances. ACS Nano 2013; 7:1755-62. [PMID: 23330883 DOI: 10.1021/nn3058505] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A novel low-cost nanoring array fabrication method that combines the process of lithographically patterned nanoscale electrodeposition (LPNE) with colloidal lithography is described. Nanoring array fabrication was accomplished in three steps: (i) a thin (70 nm) sacrificial nickel or silver film was first vapor-deposited onto a plasma-etched packed colloidal monolayer; (ii) the polymer colloids were removed from the surface, a thin film of positive photoresist was applied, and a backside exposure of the photoresist was used to create a nanohole electrode array; (iii) this array of nanoscale cylindrical electrodes was then used for the electrodeposition of gold, silver, or nickel nanorings. Removal of the photoresist and sacrificial metal film yielded a nanoring array in which all of the nanoring dimensions were set independently: the inter-ring spacing was fixed by the colloidal radius, the radius of the nanorings was controlled by the plasma etching process, and the width of the nanorings was controlled by the electrodeposition process. A combination of scanning electron microscopy (SEM) measurements and Fourier transform near-infrared (FT-NIR) absorption spectroscopy were used to characterize the nanoring arrays. Nanoring arrays with radii from 200 to 400 nm exhibited a single strong NIR plasmonic resonance with an absorption maximum wavelength that varied linearly from 1.25 to 3.33 μm as predicted by a simple standing wave model linear antenna theory. This simple yet versatile nanoring array fabrication method was also used to electrodeposit concentric double gold nanoring arrays that exhibited multiple NIR plasmonic resonances.
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Affiliation(s)
- Aaron R Halpern
- Department of Chemistry, University of California-Irvine, Irvine, California 92697, USA
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18
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Pitzschel K, Bachmann J, Montero-Moreno JM, Escrig J, Görlitz D, Nielsch K. Reversal modes and magnetostatic interactions in Fe3O4/ZrO2/Fe3O4 multilayer nanotubes. Nanotechnology 2012; 23:495718. [PMID: 23164751 DOI: 10.1088/0957-4484/23/49/495718] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Reversal modes and magnetostatic interactions of multilayered Fe(3)O(4)/ZrO(2)/Fe(3)O(4) nanotubes consisting of a ferromagnetic internal tube, an intermediate non-magnetic spacer and an external magnetic shell are investigated as a function of their geometric parameters and compared with those produced inside the pores of anodic alumina membranes by atomic layer deposition. Based on a continuum approach we obtained analytical expressions that underline the first experimental results and support their interpretation that the system of multilayer tubes behaves as the reversal of two isolated systems. It is observed that the magnetostatic interaction between both phases depends on the magnetic configurations in each phase and also on the geometrical parameters considered. These structures have potential applications in novel spintronics devices, ultra-small magnetic media and other nano-devices.
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Weber DP, Rüffer D, Buchter A, Xue F, Russo-Averchi E, Huber R, Berberich P, Arbiol J, Fontcuberta I Morral A, Grundler D, Poggio M. Cantilever magnetometry of individual Ni nanotubes. Nano Lett 2012; 12:6139-6144. [PMID: 23134122 DOI: 10.1021/nl302950u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Recent experimental and theoretical work has focused on ferromagnetic nanotubes due to their potential applications as magnetic sensors or as elements in high-density magnetic memory. The possible presence of magnetic vortex states-states which produce no stray fields-makes these structures particularly promising as storage devices. Here we investigate the behavior of the magnetization states in individual Ni nanotubes by sensitive cantilever magnetometry. Magnetometry measurements are carried out in the three major orientations, revealing the presence of different stable magnetic states. The observed behavior is well-described by a model based on the presence of uniform states at high applied magnetic fields and a circumferential onion state at low applied fields.
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Affiliation(s)
- D P Weber
- Departement Physik, Universität Basel, 4056 Basel, Switzerland
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Zu X, Gong J, Tu W, Deng Y. Selective and Sequential Re-Assembly of Patterned Block Copolymer Thin Film for Fabricating Polymeric, Inorganic, and Their Composite Nanostructured Arrays. Macromol Rapid Commun 2011; 32:1526-32. [DOI: 10.1002/marc.201100313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/09/2011] [Indexed: 02/03/2023]
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22
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Hangarter CM, Rheem Y, Stahovich T, Myung NV. Synthesis and magneto-transport properties of single PEDOT/Ni and PEDOT/Ni30Fe70 core/shell nanowires. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.03.115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Takagaki Y, Herfort J, Hilse M, Geelhaar L, Riechert H. Swingback in magnetization reversal in MnAs-GaAs coaxial nanowire heterostructures. J Phys Condens Matter 2011; 23:126002. [PMID: 21378442 DOI: 10.1088/0953-8984/23/12/126002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The reversal processes of magnetization in epitaxial MnAs nanotubes prepared by an overgrowth on the sidewall of GaAs nanowires having a diameter of 26 nm are investigated. While the magnetic hard axis is aligned in the direction of the nanowire axis, we apply an external magnetic field perpendicular to the axis to examine the flipping characteristics of magnetic moments. We determine the contributions from the substrate by a direct measurement in order to extract the magnetization of the core-shell heterostructures. The abrupt change in the thus-obtained magnetization due to a flip when the field is varied exhibits an overshoot at about 0.4 kOe for samples with a thickness of the ferromagnetic shell (40-50 nm) larger than the diameter of the core. Moreover, the peak value exceeds the value when the field is swept in the opposite direction. The magnetic hysteresis loop consequently involves line crossings. We speculate that the spin textures of domain walls in such thick hollow cylinders and their movement at the magnetization flip are affected by the geometry and magnetostatic interactions of various origins, giving rise to the anomalous behaviour.
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Affiliation(s)
- Y Takagaki
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
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Wang ZK, Zhang VL, Lim HS, Ng SC, Kuok MH, Jain S, Adeyeye AO. Nanostructured magnonic crystals with size-tunable bandgaps. ACS Nano 2010; 4:643-8. [PMID: 20099868 DOI: 10.1021/nn901171u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Just as a photonic crystal is a periodic composite composed of materials with different dielectric constants, its lesser known magnetic analogue, the magnonic crystal can be considered as a periodic composite comprising different magnetic materials. Magnonic crystals are excellent candidates for the fabrication of nanoscale microwave devices, as the wavelengths of magnons in magnonic crystals are orders of magnitude shorter than those of photons, of the same frequency, in photonic crystals. Using advanced electron beam lithographic techniques, we have fabricated a series of novel bicomponent magnonic crystals which exhibit well-defined frequency bandgaps. They are in the form of laterally patterned periodic arrays of alternating cobalt and permalloy stripes of various widths ranging from 150 to 500 nm. Investigations by Brillouin light scattering and computer modeling show that the dispersion spectrum of these crystals is strongly dependent on their structural dimensions. For instance, their first frequency bandgap is found to vary over a wide range of 1.4-2.6 gigahertz. Such a functionality permits the tailoring of the bandgap structure which controls the transmission of information-carrying spin waves in devices based on these crystals. Additionally, it is observed that the bandgap width decreases with increasing permalloy stripe width, but increases with increasing cobalt stripe width, and that the bandgap center frequency is more dependent on the stripe width of permalloy than that of cobalt. This information would be of value in the design of magnonic crystals for potential applications in the emerging field of magnonics.
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Affiliation(s)
- Zhi Kui Wang
- Department of Physics, National University of Singapore, Singapore 117542
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25
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Abstract
The magnetic configurations of barcode-type magnetic nanostructures consisting of alternate ferromagnetic and nonmagnetic layers arranged within a multilayer nanotube structure are investigated as a function of their geometry. Based on a continuum approach we have obtained analytical expressions for the energy which lead us to obtain phase diagrams giving the relative stability of characteristic internal magnetic configurations of the barcode-type nanostructures.
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Affiliation(s)
- B Leighton
- Departamento de Física, Universidad de Santiago de Chile, Avenida Ecuador 3493, 917-0124 Santiago, Chile
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Zhang L, Si HY, Zhang HL. Highly ordered fluorescent rings by “breath figures” on patterned substrates using polymer-free CdSe quantum dots. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b718643f] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Herein, a nanoscale patterning technique is demonstrated for creating twin features in polymers and metals. The process works by combining evaporative staining with a templating process. Well-ordered hexagonally arrayed double rings were fabricated using hydrophobic spherical templates. The diameter of the rings, the width of individual rings, and the spacing between concentric and adjacent rings could be tuned by varying the solution conditions. Arrays could be made without the outer ring by employing hydrophilic templates.
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Gui YS, Mecking N, Hu CM. Quantized spin excitations in a ferromagnetic microstrip from microwave photovoltage measurements. Phys Rev Lett 2007; 98:217603. [PMID: 17677808 DOI: 10.1103/physrevlett.98.217603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Indexed: 05/16/2023]
Abstract
Quantized spin excitations in a single ferromagnetic microstrip have been measured using the microwave photovoltage technique. Several kinds of spin wave modes due to different contributions of the dipole-dipole and the exchange interactions are observed. Among them are a series of distinct dipole-exchange spin wave modes, which allow us to determine precisely the subtle spin boundary condition. A comprehensive picture for quantized spin excitations in a ferromagnet with finite size is thereby established. The dispersions of the quantized spin wave modes have two different branches separated by the saturation magnetization.
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Affiliation(s)
- Y S Gui
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Canada R3T 2N2.
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Wang S, Yu GJ, Gong JL, Li QT, Xu HJ, Zhu DZ, Zhu ZY. Large-area fabrication of periodic Fe nanorings with controllable aspect ratios in porous alumina templates. Nanotechnology 2006; 17:1594-1598. [PMID: 26558565 DOI: 10.1088/0957-4484/17/6/011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Highly uniform Fe nanoring arrays in porous anodic alumina templates are fabricated by physical vapour deposition and grazing ion milling techniques. The nanorings have aspect ratios ranging from 0.8 to 4, depending on the deposition conditions. The outer diameter of the individual nanorings, and the area density and distribution patterns are completely determined by the template used. Selected-area electron diffraction reveals that these nanorings have a polycrystalline microstructure. The nanoring fabrication method demonstrated here can be extended to other materials.
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Affiliation(s)
- S Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China
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