Página 1 dos resultados de 22 itens digitais encontrados em 0.001 segundos

Determining transport efficiency for the purpose of counting and sizing nanoparticles via single particle inductively coupled plasma-mass spectrometry

Pace, Heather E.; Rogers, Nicola J.; Jarolimek, Chad; Coleman, Victoria A.; Higgins, Christopher P.; Ranville, James F.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Currently there are few ideal methods for the characterization of nanoparticles in complex, environmental samples, leading to significant gaps in toxicity and exposure assessments of nanomaterials. Single particle-inductively coupled plasma-mass spectrometry (spICP-MS) is an emerging technique that can both size and count metal-containing nanoparticles. A major benefit of the spICP-MS method is its ability to characterize nanoparticles at concentrations relevant to the environment. This paper presents a practical guide on how to count and size nanoparticles using spICP-MS. Different methods are investigated for measuring transport efficiency (i.e. nebulization efficiency), an important term in the spICP-MS calculations. In addition, an alternative protocol is provided for determining particle size that broadens the applicability of the technique to all types of inorganic nanoparticles. Initial comparison, using well-characterized, monodisperse silver nanoparticles, showed the importance of having an accurate transport efficiency value when determining particle number concentration and, if using the newly presented protocol, particle size. Ultimately, the goal of this paper is to provide improvements to nanometrology by further developing this technique for the characterization of metal-containing nanoparticles.

Frequency Noise Properties of Lasers for Interferometry in Nanometrology

Hrabina, Jan; Lazar, Josef; Holá, Miroslava; Číp, Ondřej
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 07/02/2013 EN
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In this contribution we focus on laser frequency noise properties and their influence on the interferometric displacement measurements. A setup for measurement of laser frequency noise is proposed and tested together with simultaneous measurement of fluctuations in displacement in the Michelson interferometer. Several laser sources, including traditional He-Ne and solid-state lasers, and their noise properties are evaluated and compared. The contribution of the laser frequency noise to the displacement measurement is discussed in the context of other sources of uncertainty associated with the interferometric setup, such as, mechanics, resolution of analog-to-digital conversion, frequency bandwidth of the detection chain, and variations of the refractive index of air.

Short-Range Six-Axis Interferometer Controlled Positioning for Scanning Probe Microscopy

Lazar, Josef; Klapetek, Petr; Valtr, Miroslav; Hrabina, Jan; Buchta, Zdenek; Cip, Onrej; Cizek, Martin; Oulehla, Jindrich; Sery, Mojmir
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 07/01/2014 EN
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We present a design of a nanometrology measuring setup which is a part of the national standard instrumentation for nanometrology operated by the Czech Metrology Institute (CMI) in Brno, Czech Republic. The system employs a full six-axis interferometric position measurement of the sample holder consisting of six independent interferometers. Here we report on description of alignment issues and accurate adjustment of orthogonality of the measuring axes. Consequently, suppression of cosine errors and reduction of sensitivity to Abbe offset is achieved through full control in all six degrees of freedom. Due to the geometric configuration including a wide basis of the two units measuring in y-direction and the three measuring in z-direction the angle resolution of the whole setup is minimize to tens of nanoradians. Moreover, the servo-control of all six degrees of freedom allows to keep guidance errors below 100 nrad. This small range system is based on a commercial nanopositioning stage driven by piezoelectric transducers with the range (200 × 200 × 10) μm. Thermally compensated miniature interferometric units with fiber-optic light delivery and integrated homodyne detection system were developed especially for this system and serve as sensors for othogonality alignment.

Nanometrology and its perspectives in environmental research

Kim, Hyun-A; Seo, Jung-Kwan; Kim, Taksoo; Lee, Byung-Tae
Fonte: The Korean Society of Environmental Health and Toxicology Publicador: The Korean Society of Environmental Health and Toxicology
Tipo: Artigo de Revista Científica
Publicado em 15/10/2014 EN
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Hybrid nanoparticle–microcavity-based plasmonic nanosensors with improved detection resolution and extended remote-sensing ability

Schmidt, Markus A.; Lei, Dang Yuan; Wondraczek, Lothar; Nazabal, Virginie; Maier, Stefan A.
Fonte: Nature Pub. Group Publicador: Nature Pub. Group
Tipo: Artigo de Revista Científica
Publicado em 09/10/2012 EN
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Optical nanosensors based on plasmonic nanoparticles have great potential for chemical and biological sensing applications, but their spectral detection resolution is severely constrained by their broad resonance linewidth, and their spatial sensing depth is limited to several tens of nanometres. Here we demonstrate that coupling a strong dipolar plasmonic resonance of a single metallic nanoparticle to the narrow bandwidth resonances of an optical microcavity creates a hybrid mode and discretizes the broad localized resonance, boosting the sensing figure-of-merit by up to 36 times. This cavity–nanoparticle system effectively combines the advantages of Fabry–Perot microresonators with those of plasmonic nanoparticles, providing interesting features such as remote-sensing ability, incident-angle independent resonances, strong polarization dependence, lateral ultra small sensing volume and strongly improved detection resolution. Such a hybrid system can be used not only to locally monitor specific dynamic processes in biosensing, but also to remotely sense important film parameters in thin-film nanometrology.

Nanometrology regime in length measurements of material artefacts with nominal lengths up to 100 mm

Titov, Alexandre; Massone, Carlos Alberto; Malinovsky, Igor
Fonte: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia Publicador: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia
Tipo: Trabalho apresentado em evento / Paper
ENG
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6 f. : il.; New calibrated double-sided method of interferometric length measurements with quartz reference plate is reported. The method is free from wringing errors, and can be used for the improvement of measurements of material artefacts. Limitations of the interferometric measurements are discussed. Some systematic errors are measured with a sub-nanometer resolution.

Introductory Guide to Nanometrology

HANSEN Poul-Erik; ROEBBEN Gert; BABICK Frank; BOYD Robert; BRAUN ADELINA; BUSCH I.; DANZEBRINK H.-U.; DEPERO Laura; DIRSCHERL Kai; DZIOMBA Thorsten; ERIKSSON Emma; FRANKS KATRIN; GEE Mark; JENNETT N.; KESTENS Vikram; KOENDERS Ludger; KRUMREY M.; LAUSMAA J
Fonte: European Commission and the participating consortium partners Publicador: European Commission and the participating consortium partners
Tipo: Books Formato: Printed
ENG
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This Guide introduces the reader to the science of measurements at the nanoscale, that is nanometrology. It is aimed at researchers in the nanotechnology area, for whom the metrology aspect is new, and at metrologists, interested in knowing about the specifics of metrology at the nanoscale. The Guide does not give an exhaustive review of the field. Rather it is intended to increase the general awareness of nanometrology, and its basic challenges. In a first section, three main questions are addressed: 1. What is (nano)metrology? 2. Why is nanometrology important? 3. What are the main challenges for nanometrology? The Guide continues with a section on the meaning of a number of generic metrology concepts. In the third section, the Guide illustrates some of the identified nanometrological challenges with practical examples and case studies from three different application areas (thin films, surface structures and nanoparticles). A final subsection is devoted to the emerging issue of metrology for nanobiotechnology; JRC.DG.D.2-Reference materials

European Consultation on Metrological Traceability, Standards and Dissemination of Metrology in Industrial Nanotechnology

PENDRILL Leslie; FLYS Olena; DIRSCHERL Kai; ROEBBEN Gert
Fonte: EUSPEN Publicador: EUSPEN
Tipo: Books Formato: Printed
ENG
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In support of sustainable growth in the nanomanufacturing industry, a CO-NANOMET [EU FP7 CSA-CA 218764] consultation of both the means and content of the dissemination of metrology to the workplace has been made during 2010. Programmes encouraging industry to innovate by exploiting nanometrology through local networking and through various documentary standards (i.e. written standards, i.e. norms) are found to be promising means of disseminating nanometrology to industry. These are two examples of how a European innovation infrastructure can provide support throughout the innovation process ¿ from initial idea, through design, manufacture, conformity, assessment and marketing ¿ through to the finished product. An innovation infrastructure in nanometrology will network and integrate actors in each field ¿ from policy makers to metrologists ¿ so that these can work together to tackle the major challenges.; JRC.D.2-Reference materials

European Nanometrology 2020

BURKE Theresa; LEACH Richard; BOYD Robert; GEE Mark; ROY D.; YACOOT Andrew; DANZEBRINK H.-U.; DZIOMBA Thorsten; KOENDERS Ludger; DEPERO Laura; CARNEIRO Kim; DIRSCHERL Kai; MORAZZANI Valérie; LAUSMAA Jukka; PENDRILL Leslie; PIDDUCK A. J.; ROEBBEN Gert; SA
Fonte: EUSPEN Publicador: EUSPEN
Tipo: Books Formato: Printed
ENG
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The Co-Nanomet project carried out a two year review of nanometrology status, opportunities and challenges across Europe. A set of goals and objectives have been established for European Nanometrology for the next decade (Vision 2020). The Co-Nanomet partners hope this document may act as a guide to the many bodies across Europe in their activities or responsibilities in the field of nanotechnology and related measurement requirements, as it moves into its next exciting decade.; JRC.D.2-Reference materials

Engineered nanoparticles: Nanometrology status and future needs within Europe

STINTZ Michael; BABICK Frank; ROEBBEN Gert
Fonte: Co-Nanomet Consortium Publicador: Co-Nanomet Consortium
Tipo: Articles in books Formato: Printed
ENG
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Engineered nanoparticles (ENPs) are particles designed and produced to have all external dimensions in the nanoscale (between approximately 1 nm and 100 nm). ENPs and their agglomerates and aggregates have been used in many industrial applications for many years. The recent increase in the number of different kinds of ENPs and the broader range and understanding of their functional properties promise much for future applications. However there are Health, Safety and Environmental (HSE) concerns because of findings that suggest for some ENPs a different toxicity than that of the bulk material of the same composition. To profit fully from the potential of ENPs and to responsibly deal with the HSE concerns requires the development of scientifically sound classification methods for nanoparticles, distinguishing them in terms of their production method, but also in terms of their basic physico-chemical characteristics and properties. The Co-Nanomet ENP Action Group addressed the related measurement issues with the purpose of identifying and promoting metrology solutions for both airborne and suspended ENPs.; JRC.D.2-Reference materials

Application d'une nouvelle conception d'architecture à une machine de mesure de résolution nanométrique Application of a new architecture design to a measuring machine with a nanometric resolution

LAHOUSSE, Ludovic; DAVID, Jean-Marie; LELEU, Stéphane; VAILLEAU, Georges-Pierre; DUCOURTIEUX, Sébastien
Fonte: Laboratoire National de Métrologie et d'Essais Publicador: Laboratoire National de Métrologie et d'Essais
FR
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The purpose of this paper is to present original concepts offering an uncertainty control advancement for measuring machines. Those concepts were developed from the analysis of phenomena that reduce the machine accuracy constructed around principles of standard architecture. A machine being developed is a concrete materialization of those concepts.

CALIBRATION OF CAPACITIVE SENSORS AND ELECTRONIC LEVELS FOR THE STRAIGHTNESS MEASUREMENTS USING MULTIPROBE METHOD

BORIPATKOSOL, Siriwan; LELEU, Stéphane; COOREVITS, Thierry; GIBARU, Olivier
Fonte: Laboratoire National de Métrologie et d'Essais Publicador: Laboratoire National de Métrologie et d'Essais
EN
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In this work, the straightness length 300 mm measurement under nanometer uncertainty. The proposed methodology represents a process known as propagation using the assumption of small displacement which leads to solving an overdetermined linear system. The experimental studies were carried out on the capacitive sensors and electronic levels. The least squares mathematic method is apply to calculate the optimal solution. This method requires taking into account the uncertainties of the two different types of sensors leads to method of weighted least squares. The first step is to calibrate the sensors and to estimate the effect on the calculated straightness.

Z calibration of the LNE ultra precision coordinate measuring machine

LAHOUSSE, Ludovic; LELEU, Stéphane; DAVID, Jean-Marie; GIBARU, Olivier; DUCOURTIEUX, Sébastien
Fonte: EUSPEN Publicador: EUSPEN
EN
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The Laboratoire National de Métrologie et d’Essais (LNE) has developed an innovative ultra precision coordinate measuring machine [1,2] traceable to the national length standard. This machine can be equipped with different kinds of sensors and is dedicated to the measurement with nanometer uncertainties of features, standards and in more general way three-dimensional objects. The measuring range is 300 mm x 300 mm x 50 μm. The objective in term of uncertainty is to reach 30 nm in X and Y directions for a 300 mm displacement and about few nanometers for the 50 μm vertical displacement. For the geometric calibration of this machine, dedicated procedures have been developed. The present paper will focus more specifically on the one used for the Z calibration.

LNE Activies in Nanometrology: flatness reference calibration algorithm

LAHOUSSE, Ludovic; BORIPATKOSOL, Siriwan; LELEU, Stéphane; DAVID, Jean-Marie; DUCOURTIEUX, Sébastien; COOREVITS, Thierry; GIBARU, Olivier
Fonte: EUSPEN Publicador: EUSPEN
EN
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27.51%
The Laboratoire National de Métrologie et d’Essais (LNE) has developed an innovative ultra precision coordinate measuring machine [LAH07] traceable to the national length standard to measure three-dimensional objects with nanometric uncertainties (figure 1). The measuring range is 300 mm x 300 mm x 50 μm. The objective in term of uncertainty is to reach 30 nm in X and Y directions for a displacement of 300 mm and about few nanometers for a vertical displacement of 50 μm. On this machine, we use four capacitive sensors to measure the position along z direction. These sensors target the flat surface of cylinders (300 mm diameter) used as flatness references. To measure the shape of these aluminum references with nanometric uncertainties, we propose a measurement method based on a propagation process in which we introduce an angular measurement to compensate the curvature error inherent in this method. The measurement process uses the same sensor technology (capacitive sensor) we use on the machine. This paper presents the measurement method, its validation and the first results.

Traceable GISAXS measurements for pitch determination of a 25 nm self-assembled polymer grating

Wernecke, Jan; Krumrey, Michael; Hoell, Armin; Kline, R. Joseph; Liu, Hung-kung; Wu, Wen-li
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 31/07/2014
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The feature sizes of only a few nanometers in modern nanotechnology and next-generation microelectronics continually increase the demand for suitable nanometrology tools. Grazing incidence small-angle X-ray scattering (GISAXS) is a versatile technique to measure lateral and vertical sizes in the nm-range, but the traceability of the obtained parameters, which is a prerequisite for any metrological measurement, has not been demonstrated so far. In this work, the first traceable GISAXS measurements, demonstrated with a self-assembled block copolymer grating structure with a nominal pitch of 25 nm, are reported. The different uncertainty contributions to the obtained pitch value of 24.83(9) nm are discussed individually. The main uncertainty contribution results from the sample-detector distance and the pixel size measurement, whereas the intrinsic asymmetry of the scattering features is of minor relevance for the investigated grating structure. The uncertainty analysis provides a basis for the evaluation of the uncertainty of GISAXS data in a more general context, for example in numerical data modeling.; Comment: 9 pages, 6 figures; submitted to Journal of Applied Crystallography

Twisted ultrathin silicon nanowires: a possible torsion electromechanical nanodevice

Cott-Garcia, Joelson; Justo, Joao F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/11/2014
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Nanowires have been considered for a number of applications in nanometrology. In such a context, we have explored the possibility of using ultrathin twisted nanowires as torsion nanobalances to probe forces and torques at molecular level with high precision, a nanoscale system analogous to the Coulomb's torsion balance electrometer. In order to achieve this goal, we performed a first principles investigation on the structural and electronic properties of twisted silicon nanowires, in their pristine and hydrogenated forms. The results indicated that wires with pentagonal and hexagonal cross sections are the thinnest stable silicon nanostructures. Additionally, all wires followed a Hooke's law behavior for small twisting deformations. Hydrogenation leads to spontaneous twisting, but with angular spring constants considerably smaller than the ones for the respective pristine forms. We observed considerable changes on the nanowire electronic properties upon twisting, which allows to envision the possibility of correlating the torsional angular deformation with the nanowire electronic transport. This could ultimately allow a direct access to measurements on interatomic forces at molecular level.

Micro-Raman Spectroscopy of Mechanically Exfoliated Few-Quintuple Layers of Bi(2)Te(3), Bi(2)Se(3) and Sb(2)Te(3) Materials

Shahil, K. M. F.; Hossain, M. Z.; Goyal, V.; Balandin, A. A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/01/2012
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Bismuth telluride - Bi(2)Te(3)- and related compounds have recently attracted strong interest owing to the discovery of the topological insulator properties in many members of this family of materials. The few-quintuple films of these materials are particularly interesting from the physics point of view. We report results of the micro-Raman spectroscopy study of the "graphene-like" exfoliated few-quintuple layers of Bi(2)Te(3), Bi(2)Se(3) and Sb(2)Te(3). It is found that crystal symmetry breaking in few-quintuple films results in appearance of A1u-symmetry Raman peaks, which are not active in the bulk crystals. The scattering spectra measured under the 633-nm wavelength excitation reveals a number of resonant features, which could be used for analysis of the electronic and phonon processes in these materials. In order to elucidate the influence of substrates on the few-quintuple-thick topological insulators we examined the Raman spectra of these films placed on mica, sapphire and hafnium-oxide substrates. The obtained results help to understand the physical mechanisms of Raman scattering in the few-quintuple-thick films and can be used for nanometrology of topological insulator films on various substrates.; Comment: 19 pages; 7 figures

Ultraviolet Raman Spectroscopy of Single and Multi-layer Graphene

Calizo, Irene; Bejenari, Igor; Rahman, Muhammad; Liu, Guanxiong; Balandin, Alexander A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/03/2009
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We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band intensity undergoes severe quenching. The evolution of the ratio of the intensities of the G and 2D peaks, I(G)/I(2D), as the number of graphene layers n changes from n=1 to n=5, is different in UV Raman spectra from that in conventional visible Raman spectra excited at the 488 nm and 633 nm wavelengths. The 2D band under UV excitation shifts to larger wave numbers and is found near 2825 1/cm. The observed UV Raman features of graphene were explained by invoking the resonant scattering model. The obtained results contribute to the Raman nanometrology of graphene by providing an additional metric for determining the number of graphene layers and assessing its quality.; Comment: 18 pages; 5 figures; submitted for publication on February 20, 2009

Crystal Symmetry Breaking in Few-Quintuple Bismuth Telluride Films: Applications in Nanometrology of Topological Insulators

Shahil, K. M. F.; Hossain, M. Z.; Teweldebrhan, D.; Balandin, A. A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/03/2010
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We report results of micro-Raman spectroscopy investigation of the "graphene-like" mechanically exfoliated single-crystal bismuth telluride films with the thickness ranging from a few-nm-range to bulk limit. It is found that the optical phonon mode A1u, which is not-Raman active in bulk bismuth telluride crystals, appears in the atomically-thin films due to crystal-symmetry breaking. The intensity ratios of the out-of-plane A1u and A1g modes to the in-plane Eg mode grow with decreasing film thickness. The evolution of Raman signatures with the film thickness can be used for identification of bismuth telluride crystals with the thickness of few-quintuple layers, which are important for topological insulator and thermoelectric applications.; Comment: 13 pages, 2 tables, 3 figures; to be presented at MRS Spring Meeting, 2010

Polarization Controlled Directional Scattering for Nanoscopic Position Sensing

Neugebauer, Martin; Woźniak, Paweł; Bag, Ankan; Leuchs, Gerd; Banzer, Peter
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 06/11/2015
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Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has been directed towards high-refractive index materials such as silicon as an integral part of the antenna design. The development is motivated by the rich spectral properties of individual high-refractive index nanoparticles, featuring magnetic and electric resonances in the visible regime, whose interference may yield remarkably strong directivity. Here, we use tightly focused radially polarized light for controlled excitation of a spherical silicon nanoantenna. The resultant emission can be highly directional, depending on the antenna's position relative to the focus. This approach finds application as a novel position sensing technique, a discipline, which is of paramount importance in modern nanometrology, because of its special role in super-resolution microscopy. We yield a lateral resolution in the Angstrom regime.; Comment: 8 pages, 6 figures