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1
المؤلفون: Hidemasa Yamane, Tatsuya Kameyama, Yan Jun Li, Junsuke Yamanishi, Seiya Koyama, Yoshitaka Naitoh, Yasuhiro Sugawara, Nobuhiko Yokoshi, Hajime Ishihara, Tsukasa Torimoto
المصدر: Nature Communications, Vol 12, Iss 1, Pp 1-7 (2021)
Nature Communicationsمصطلحات موضوعية: Heterodyne, Materials science, Science, Optical force, Nanophotonics, General Physics and Astronomy, Physics::Optics, 02 engineering and technology, Optical field, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Article, Condensed Matter::Materials Science, 0103 physical sciences, Microscopy, 010306 general physics, Nanophotonics and plasmonics, Multidisciplinary, business.industry, Imaging and sensing, General Chemistry, 021001 nanoscience & nanotechnology, Pressure-gradient force, Quantum dot, Optoelectronics, Nanometre, 0210 nano-technology, business, Other nanotechnology
الوصف: Three-dimensional (3D) information of the optical response in the nanometre scale is important in the field of nanophotonics science. Using photoinduced force microscopy (PiFM), we can visualize the nano-scale optical field using the optical gradient force between the tip and sample. Here, we demonstrate 3D photoinduced force field visualization around a quantum dot in the single-nanometre spatial resolution with heterodyne frequency modulation technique, using which, the effect of the photothermal expansion of the tip and sample in the ultra-high vacuum condition can be avoided. The obtained 3D mapping shows the spatially localized photoinduced interaction potential and force field vectors in the single nano-scale for composite quantum dots with photocatalytic activity. Furthermore, the spatial resolution of PiFM imaging achieved is ~0.7 nm. The single-nanometer scale photoinduced field visualization is crucial for applications such as photo catalysts, optical functional devices, and optical manipulation.
Direct visualisation of 3D vector distributions of photoinduced fields can shed light on the optical and mechanical behaviour of different materials. Here, the authors demonstrate such visualisation using photoinduced force microscopy by observing the optical gradient force at the nanometer scale. -
2
المؤلفون: Avinash Singh Nayal, Rajmohan Muthaiah, Fatema Tarannum, Jivtesh Garg, Swapneel Danayat, Roshan Sameer Annam
المصدر: RSC Advances. 10:42628-42632
مصطلحات موضوعية: Length scale, Work (thermodynamics), Materials science, Condensed matter physics, Hexagonal crystal system, Phonon, General Chemical Engineering, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Transverse plane, Thermal conductivity, 0103 physical sciences, Perpendicular, Nanometre, 010306 general physics, 0210 nano-technology
الوصف: In this work, we report a high thermal conductivity (k) of 162 W m−1 K−1 and 52 W m−1 K−1 at room temperature, along the directions perpendicular and parallel to the c-axis, respectively, of bulk hexagonal BC2P (h-BC2P), using first-principles calculations. We systematically investigate elastic constants, phonon group velocities, phonon linewidths and mode thermal conductivity contributions of transverse acoustic (TA), longitudinal acoustic (LA) and optical phonons. Interestingly, optical phonons are found to make a large contribution of 30.1% to the overall k along a direction perpendicular to the c-axis at 300 K. BC2P is also found to exhibit high thermal conductivity at nanometer length scales. At 300 K, a high k value of ∼47 W m−1 K−1 is computed for h-BC2P at a nanometer length scale of 50 nm, providing avenues for achieving efficient nanoscale heat transfer.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::063b6b787c78895d269e2985c37b7921
https://doi.org/10.1039/d0ra08444a -
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المصدر: Physical Chemistry Chemical Physics. 22:10833-10837
مصطلحات موضوعية: Materials science, Graphene, Bilayer, Physics::Optics, General Physics and Astronomy, 02 engineering and technology, Dielectric, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Molecular dynamics, law, Chemical physics, 0103 physical sciences, Monolayer, Perpendicular, Nanometre, Physical and Theoretical Chemistry, 010306 general physics, 0210 nano-technology, Anisotropy
الوصف: Water presents puzzling properties once it gets confined down to the scale below about one nanometer, in particular its dielectric response becomes highly anisotropic in inhomogeneous environments such as slit pores. Here, we analyze the dielectric response of water within graphene slit pores in different confinement regimes based on molecular dynamics simulations. Our data quantify how the distinctly different parallel (in-plane) and perpendicular (out-of-plane) dielectric profiles change upon two-dimensional confinement from wide pores - featuring bulk-like behavior in between typical interfacial water layers - down to the water bilayer and monolayer limit. In addition, we show that simulating water in such narrow pores requires specific water-graphene interaction parameters different from those usually employed for interfaces.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4af16b963a0cc9bb3fa46d3da3151748
https://doi.org/10.1039/d0cp00916d -
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المؤلفون: Jayasri Dontabhaktuni, Slobodan Zumer, Miha Ravnik
المصدر: Crystals, vol. 8, no. 7, 275, 2018.
Crystals
Volume 8
Issue 7
Crystals, Vol 8, Iss 7, p 275 (2018)مصطلحات موضوعية: quasi crystals, tekoči kristali, Materials science, General Chemical Engineering, udc:538.9, Nanoparticle, 02 engineering and technology, 01 natural sciences, Topological defect, topološki defekti, Inorganic Chemistry, liquid crystals, Liquid crystal, colloids, 0103 physical sciences, lcsh:QD901-999, Molecule, General Materials Science, optical manipulation, 010306 general physics, koloidi, samourejanje, Quasicrystal, self-assembly, 021001 nanoscience & nanotechnology, Condensed Matter Physics, kvazikristali, cholesteric, Condensed Matter::Soft Condensed Matter, Chemical physics, Nanometre, Self-assembly, lcsh:Crystallography, 0210 nano-technology, topological defects, nematic, Lasing threshold
الوصف: Quasicrystalline ordering was first observed in synthetic multi-component metallic alloys. These solid state materials exhibit quasicrystalline atomic ordering at nanometer length scales. Softmatter systems are another class of versatile materials that can exhibit quasicrystalline ordering across supra-nanometer (>
10 nm) to supra-micrometer (>
10 &mu
m) length scales as recently observed in materials like-supramolecular dendritic molecules, ABC star polymers, binary nanoparticle systems and block co-polymers in condensed matter systems. The underlying mechanism in most of these soft quasicrystals seems to be the presence of two or more length scales in the system. Another class of development in self-assembled quasicrystals in softmatter is being observed in low molecular weight chiral and achiral nematic liquid crystals. Liquid crystal forms an efficient matrix for self- and directed-assemblies of colloidal structures where surface and geometry-tuning the particles in nematic liquid crystals gives rise to complex inter-particle interactions while the long-range order results in self-assembled structures of higher order rotational symmetries. Furthermore, there has also been attempts to generate colloidal quasicrystalline defect structures by directing the assemblies using multiple and single beam lasing techniques. In the present article, we will review self- and assisted-assembly of quasicrystalline structures in nematic liquid crystals (both chiral and achiral) and discuss the underlying mechanisms.وصف الملف: application/pdf; text/url
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المؤلفون: Thierry Ondarçuhu, Sylvain Franiatte, Philippe Tordjeman
المساهمون: Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
المصدر: Physical Review Letters
Physical Review Letters, American Physical Society, 2021, 127 (6), pp.065501. ⟨10.1103/PhysRevLett.127.065501⟩مصطلحات موضوعية: Materials science, Capillary action, Mécanique des fluides, General Physics and Astronomy, Wetting, 02 engineering and technology, 01 natural sciences, Interfacial phenomena, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Adsorption, Desorption, 0103 physical sciences, Molecule, Nanosciences, 010306 general physics, Line (formation), Contact line, 021001 nanoscience & nanotechnology, Chemical physics, Atomic force microscopy (AFM), Nanometre, Contact line dynamics, 0210 nano-technology
الوصف: International audience; The interaction of the contact line with topographical or chemical defects at the nanometer scale sets the macroscopic wetting properties of a liquid on a solid substrate. Based on specific atomic force microscopy (AFM) experiments, we demonstrate that molecules physically sorbed on a surface are removed by a dynamic contact line. The mechanism of molecules desorption is directly determined by the capillary force exerted at the contact line on the molecules. We also emphasize the potential of AFM to clearly decorrelate the effects of topographical and chemical defects and monitor, with a subsecond time resolution, the dynamics of molecules adsorption on a surface.
وصف الملف: application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::27625299b8ef78f1bd7759b83d4b8d81
https://hal.archives-ouvertes.fr/hal-03381912/document -
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المؤلفون: Irina A. Kolmychek, E. A. Mamonov, N. S. Gusev, Tatiana V. Murzina, Igor Yu. Pashen’kin, Anton I. Maydykovskiy, V.V. Radovskaya, Alexei Temiryazev, Marina Temiryazeva
المصدر: Materials
Volume 14
Issue 13
Materials, Vol 14, Iss 3573, p 3573 (2021)مصطلحات موضوعية: Technology, Nanostructure, Materials science, Physics::Optics, 02 engineering and technology, 01 natural sciences, magnetic thin films, Article, Magnetization, 0103 physical sciences, General Materials Science, Symmetry breaking, 010306 general physics, Spin (physics), Microscopy, QC120-168.85, Condensed matter physics, second harmonic generation, QH201-278.5, Second-harmonic generation, Engineering (General). Civil engineering (General), 021001 nanoscience & nanotechnology, TK1-9971, inhomogeneous magnetization, Descriptive and experimental mechanics, Ferromagnetism, Nanometre, Electrical engineering. Electronics. Nuclear engineering, TA1-2040, 0210 nano-technology, Intensity (heat transfer)
الوصف: Properties of nanolayers can substantially differ from those of bulky materials, in part due to pronounced interface effects. It is known that combinations of layers of heavy and ferromagnetic metals leads to the appearance of specific spin textures induced by interface-induced Dzyaloshinskyi–Moria interaction (DMI), which attracts much interest and requires further studies. In this paper, we study magneto-optical effects in two- and three-layer films composed of a few nanometer thick Co layer adjacent to nanofilms of non-magnetic materials (Pt, W, Cu, Ta, MgO). For experimental studies of the interface magnetization-induced effects, we used the optical second harmonic generation (SHG) technique known for its high sensitivity to the symmetry breaking. We found that the structural asymmetry leads to the increase of the averaged SHG intensity, as well as to the magnetic field-induced effects in SHG. Moreover, by choosing the proper geometry of the experiment, we excluded the most studied linear in magnetization SHG contributions and, thus, succeeded in studying higher order in magnetization and non-local magnetic effects. We revealed odd in magnetization SHG effects consistent with the phenomenological description involving inhomogeneous (gradient) magnetization distribution at interfaces and found them quite pronounced, so that they should be necessarily taken into account when analyzing the non-linear magneto-optical response of nanostructures.
وصف الملف: application/pdf
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المؤلفون: Mariana Verezhak, Ludovic Thilly, Steven Van Petegem, Ana Diaz, Angel Rodriguez-Fernandez, Vincent Jacques, Andreas Menzel, Klaus Wakonig, Dmitry Karpov, Pierre Godard
المساهمون: Paul Scherrer Institute (PSI), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
المصدر: Physical Review B
Physical Review B, American Physical Society, 2021, 103 (14), ⟨10.1103/PhysRevB.103.144107⟩
Physical Review B, 103 (14)مصطلحات موضوعية: Diffraction, [PHYS]Physics [physics], Fabrication, Materials science, business.industry, Resolution (electron density), X-ray, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Characterization (materials science), Optics, Transmission electron microscopy, 0103 physical sciences, Nanometre, 010306 general physics, 0210 nano-technology, business, Image resolution, ComputingMilieux_MISCELLANEOUS
الوصف: Strain and defects in crystalline materials are responsible for the distinct mechanical, electric, and magnetic properties of a desired material, making their study an essential task in material characterization, fabrication, and design. Existing techniques for the visualization of strain fields, such as transmission electron microscopy and diffraction, are destructive and limited to thin slices of the materials. On the other hand, nondestructive x-ray imaging methods either have a reduced resolution or are not robust enough for a broad range of applications. Here we present x-ray ptychographic topography, a method for strain imaging, and demonstrate its use on an InSb micropillar after microcompression, where the strained region is visualized with a spatial resolution of 30 nm. Thereby, x-ray ptychographic topography proves itself as a robust nondestructive approach for the imaging of strain fields within bulk crystalline specimens with a spatial resolution of a few tens of nanometers.
Physical Review B, 103 (14)
ISSN:1098-0121
ISSN:0163-1829
ISSN:1550-235X
ISSN:0556-2805
ISSN:2469-9969
ISSN:1095-3795
ISSN:2469-9950وصف الملف: application/application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e92391d057a553323d1d6ad5c6d1ca2a
https://hal.archives-ouvertes.fr/hal-03329650 -
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المؤلفون: Jakob Andreasson, Janos Hajdu, Alfonso M. Gañán-Calvo, Kerstin Mühlig, Daniel S. D. Larsson, Martin Svenda
المصدر: Journal of Applied Crystallography. 52:800-808
مصطلحات موضوعية: Aqueous solution, Materials science, Electrospray ionization, Nozzle, Theoretical models, 02 engineering and technology, Electrolyte, 021001 nanoscience & nanotechnology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Physics::Fluid Dynamics, Chemical physics, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Nanometre, 010306 general physics, 0210 nano-technology, Environmental scanning electron microscope, Droplet size
الوصف: This paper reports on improved techniques to create and characterize nanometre-sized droplets from dilute aqueous solutions by using a gas dynamic virtual nozzle (GDVN). It describes a method to measure the size distribution of uncharged droplets, using an environmental scanning electron microscope, and provides theoretical models for the droplet sizes created. The results show that droplet sizes can be tuned by adjusting the gas and liquid flow rates in the GDVN, and at the lowest liquid flow rates, the size of the water droplets peaks at about 120 nm. This droplet size is similar to droplet sizes produced by electrospray ionization but requires neither electrolytes nor charging of the solution. The results presented here identify a new operational regime for GDVNs and show that predictable droplet sizes, comparable to those obtained by electrospray ionization, can be produced by purely mechanical means in GDVNs.
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المؤلفون: Sergey Sukhov
المصدر: Journal of Communications Technology and Electronics. 63:1137-1142
مصطلحات موضوعية: Radiation, Materials science, Microscope, Field (physics), Nanowire, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, law.invention, Resonator, law, Quantum dot, 0103 physical sciences, Nanometre, Electrical and Electronic Engineering, 010306 general physics, 0210 nano-technology, Nanoscopic scale, Plasmon
الوصف: Advanced techniques for optical manipulation of nanoscale objects are presented. Possible mechanisms of enhancement of the effect of light on nanoobjects are listed. Enhancements by plasmon effects, field amplification in high-Q resonators, and collective effects are characterized. These methods are suitable for manipulation of various nanoobjects: quantum dots, nanowires, nanotubes, and cell organelles. Techniques for the measurement of forces at nanometer scales with atomic force microscopes are discussed.
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المؤلفون: Hiroshi Ota, Yasunori Senba, Tomohiro Matsushita, Takayuki Muro, Fumihiko Matsui, Yoshiki Fujita
المصدر: Surface and Interface Analysis. 51:74-78
مصطلحات موضوعية: Diffraction, Surface (mathematics), Materials science, Micrometer scale, Nanotechnology, 02 engineering and technology, Surfaces and Interfaces, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, 0103 physical sciences, Microscopy, Materials Chemistry, Nanometre, Graphite, 010306 general physics, 0210 nano-technology
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