... phenomena. In fact, questions surrounding the issue of visualisation are particularly interes... more ... phenomena. In fact, questions surrounding the issue of visualisation are particularly interesting when con-... 2 An experimental procedure of Stephen Gray's: A 1746 copperplate engraving published in William ... has more decorative qualities than other illustrations. visual spark). ...
... 17. N. Zimmer, B. Holst, Interdisc. Sci. Rev. 27, 257 (2002). The Paucity of Grants Among You... more ... 17. N. Zimmer, B. Holst, Interdisc. Sci. Rev. 27, 257 (2002). The Paucity of Grants Among Young Scientists ... www.sciencemag.org SCIENCE VOL 298 20 DECEMBER 2002 2329 partments, who felt that opening such a Pan-dora's box (their words) would be undesir-able. ...
2009 9th Ieee Conference on Nanotechnology, Jul 26, 2009
Abstract Beams of neutral atoms or molecules at thermal energies are already known as a powerful ... more Abstract Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for structural and dynamical analysis of solid surface properties, and in particular characteristics on the nanometer scale. By the implementation of suitable optical ...
An unusual strain relaxation mechanism has been observed during the growth of ultrathin Cu films ... more An unusual strain relaxation mechanism has been observed during the growth of ultrathin Cu films on Pt(111) at a substrate temperature of 450 K. After the completion of a pseudomorphic first Cu monolayer, the Pt substrate undergoes a reconstruction which is visible in the pseudomorphic Cu overlayer. Using in situ helium atom scattering, interlayer mass transport is observed as ad-atoms are incorporated into the substrate. Scanning tunneling microscopy measurements allow us to label the substrate reconstruction as being similar in nature to the ``star'' network of the reconstructed Pt(111) surface.
Low energy (thermal) free jet (supersonic) molecular beams are used in a range of applications fr... more Low energy (thermal) free jet (supersonic) molecular beams are used in a range of applications from surface science and surface deposition to quantum coherence and gas kinetics experiments. A free jet molecular beam is created by a gas expansion from a high pressure reservoir through a small aperture (nozzle). The nozzle typically has a diameter of 2-20 μm. The central part of the beam is selected using a skimmer, typically up to 500 μm in diameter. Recent years have seen the introduction of highly spatially confined beam sources based on micrometer skimmers and micrometer or even sub-micrometer nozzles. Such sources have been applied, for example, in the investigation of superfluidity and in neutral helium microscopy. However, up till now no source design allowing the precise positioning of the micro-skimmer relative to the nozzle has been available. This is an important issue because the relative position of skimmer and nozzle can influence the beam properties considerably. Here w...
High detection efficiency combined with spatial resolution on a nm-scale makes the field ionizati... more High detection efficiency combined with spatial resolution on a nm-scale makes the field ionization process a promising candidate for spatially resolved neutral particles detection. The effective cross-sectional area sigma(eff) can serve as a measure for the effectiveness of such a field ion detector. In the present contribution, we combine quantum-mechanical calculations of the field-modified electron density distribution near the tungsten tip surface and of the resulting local field distributions, performed using the functional integration method, with a classical treatment of the atom trajectories approaching the tip in order to calculate the sigma(eff) values for ionization of free He atoms over an apex of a tungsten field emitter tip. The calculated values are compared with experimental data for supersonic He atomic beams at two different temperatures 95 and 298K.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2013
ABSTRACT Metal nanoparticles have interesting optical properties, in particular, the localized su... more ABSTRACT Metal nanoparticles have interesting optical properties, in particular, the localized surface plasmon resonance effect (LSPR), which can be used in a range of applications such as photon detectors, photovoltaics, and biosensors. The theory of LSPR is complex, and hence, it is very important to develop reliable model systems, where the properties of the particles can be investigated under controlled conditions. Important parameters, which influence the frequency and intensity of the LSPR, are size, shape, and spacing of the individual nanoparticles, as well as the metal and the surrounding medium. For applications related to photovoltaics, in particular, it is important to investigate the effect of nanoparticles, covering large areas to mimic realistic operating conditions. Here, the authors present a preparation method and optical investigations of LSPR for large arrays (5 mm × 5 mm) of gold and aluminum nanoparticles ranging in diameter from 44 to 140 nm (corresponding to around 120 million particles). The authors compare and see that the LSPR measurements have a good agreement with previously published results from the literature. These measurements from the literature were mostly performed on much smaller arrays. The authors briefly discuss the effect of depositing the nanoparticles on an indium-tin-oxide-coated glass instead of a bare glass substrates and point out an interesting scanning electron microscopy imaging artifact when measuring the samples deposited directly on nonconductive substrates. A shrinkage effect is seen due to sample charging, causing the measured dimensions to appear smaller than the physical size of the object.
Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 2013
ABSTRACT Nanostructured dielectric membranes are used in several applications ranging from de Bro... more ABSTRACT Nanostructured dielectric membranes are used in several applications ranging from de Broglie matter-wave optical elements to photonic crystals. Precise pattern transfer and high aspect ratio structures are crucial for many applications. The authors present an improved method for direct patterning on free-standing, dielectric membranes using electron-beam (e-beam) lithography. The method is based on an advanced etchmask that both reduces charging and allows for tuning of the etch mask thickness to support high aspect ratios even for small structures. The authors etched structures as small as 50 nm radius holes in a 150 nm thick membrane and achieved aspect ratios of up to 1.3 for this structure size range. The etch mask thickness can be tuned to achieve the required aspect ratio. The etchmask is composed of a three layer stack consisting of poly(methyl methacrylate), SiO2 and an antireflective coating polymer. Scanning-electron micrographs of membranes produced with the fabrication method are presented.
Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for... more Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for structural and dynamical analysis of solid surface properties, and in particular characteristics on the nanometer scale. By the implementation of suitable optical ...
Identifying and distinguishing between natural textile fibres is an important task in both archae... more Identifying and distinguishing between natural textile fibres is an important task in both archaeology and criminology. Wool, silk and cotton fibres can readily be distinguished from the textile bast fibres flax, nettle/ramie, hemp and jute. Distinguishing between the bast fibres is, however, not easily done and methods based on surface characteristics, chemical composition and cross section size and shape are not conclusive. A conclusive method based on X-ray microdiffraction exists, but as the method requires the use of a synchrotron it is not readily available. In this paper we present a simple procedure for identifying the above mentioned textile bast fibres. The procedure is based on measuring the fibrillar orientation with polarised light microscopy and detecting the presence of calcium oxalate crystals (CaC2O4) in association with the fibres. To demonstrate the procedure, a series of fibre samples of flax, nettle, ramie, hemp and jute were investigated. The results are presented here. An advantage of the procedure is that only a small amount of fibre material is needed.
Seminal field ionization detection of a supersonic helium beam is reported, including intensity m... more Seminal field ionization detection of a supersonic helium beam is reported, including intensity measurements on a continuous beam and time-of-flight measurements on a chopped beam. Also unique to these experiments is the care with which the field ionization tip was prepared and characterized prior to its use. Comparative measurements on a static helium gas are presented and the effective detection
... phenomena. In fact, questions surrounding the issue of visualisation are particularly interes... more ... phenomena. In fact, questions surrounding the issue of visualisation are particularly interesting when con-... 2 An experimental procedure of Stephen Gray's: A 1746 copperplate engraving published in William ... has more decorative qualities than other illustrations. visual spark). ...
... 17. N. Zimmer, B. Holst, Interdisc. Sci. Rev. 27, 257 (2002). The Paucity of Grants Among You... more ... 17. N. Zimmer, B. Holst, Interdisc. Sci. Rev. 27, 257 (2002). The Paucity of Grants Among Young Scientists ... www.sciencemag.org SCIENCE VOL 298 20 DECEMBER 2002 2329 partments, who felt that opening such a Pan-dora's box (their words) would be undesir-able. ...
2009 9th Ieee Conference on Nanotechnology, Jul 26, 2009
Abstract Beams of neutral atoms or molecules at thermal energies are already known as a powerful ... more Abstract Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for structural and dynamical analysis of solid surface properties, and in particular characteristics on the nanometer scale. By the implementation of suitable optical ...
An unusual strain relaxation mechanism has been observed during the growth of ultrathin Cu films ... more An unusual strain relaxation mechanism has been observed during the growth of ultrathin Cu films on Pt(111) at a substrate temperature of 450 K. After the completion of a pseudomorphic first Cu monolayer, the Pt substrate undergoes a reconstruction which is visible in the pseudomorphic Cu overlayer. Using in situ helium atom scattering, interlayer mass transport is observed as ad-atoms are incorporated into the substrate. Scanning tunneling microscopy measurements allow us to label the substrate reconstruction as being similar in nature to the ``star'' network of the reconstructed Pt(111) surface.
Low energy (thermal) free jet (supersonic) molecular beams are used in a range of applications fr... more Low energy (thermal) free jet (supersonic) molecular beams are used in a range of applications from surface science and surface deposition to quantum coherence and gas kinetics experiments. A free jet molecular beam is created by a gas expansion from a high pressure reservoir through a small aperture (nozzle). The nozzle typically has a diameter of 2-20 μm. The central part of the beam is selected using a skimmer, typically up to 500 μm in diameter. Recent years have seen the introduction of highly spatially confined beam sources based on micrometer skimmers and micrometer or even sub-micrometer nozzles. Such sources have been applied, for example, in the investigation of superfluidity and in neutral helium microscopy. However, up till now no source design allowing the precise positioning of the micro-skimmer relative to the nozzle has been available. This is an important issue because the relative position of skimmer and nozzle can influence the beam properties considerably. Here w...
High detection efficiency combined with spatial resolution on a nm-scale makes the field ionizati... more High detection efficiency combined with spatial resolution on a nm-scale makes the field ionization process a promising candidate for spatially resolved neutral particles detection. The effective cross-sectional area sigma(eff) can serve as a measure for the effectiveness of such a field ion detector. In the present contribution, we combine quantum-mechanical calculations of the field-modified electron density distribution near the tungsten tip surface and of the resulting local field distributions, performed using the functional integration method, with a classical treatment of the atom trajectories approaching the tip in order to calculate the sigma(eff) values for ionization of free He atoms over an apex of a tungsten field emitter tip. The calculated values are compared with experimental data for supersonic He atomic beams at two different temperatures 95 and 298K.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2013
ABSTRACT Metal nanoparticles have interesting optical properties, in particular, the localized su... more ABSTRACT Metal nanoparticles have interesting optical properties, in particular, the localized surface plasmon resonance effect (LSPR), which can be used in a range of applications such as photon detectors, photovoltaics, and biosensors. The theory of LSPR is complex, and hence, it is very important to develop reliable model systems, where the properties of the particles can be investigated under controlled conditions. Important parameters, which influence the frequency and intensity of the LSPR, are size, shape, and spacing of the individual nanoparticles, as well as the metal and the surrounding medium. For applications related to photovoltaics, in particular, it is important to investigate the effect of nanoparticles, covering large areas to mimic realistic operating conditions. Here, the authors present a preparation method and optical investigations of LSPR for large arrays (5 mm × 5 mm) of gold and aluminum nanoparticles ranging in diameter from 44 to 140 nm (corresponding to around 120 million particles). The authors compare and see that the LSPR measurements have a good agreement with previously published results from the literature. These measurements from the literature were mostly performed on much smaller arrays. The authors briefly discuss the effect of depositing the nanoparticles on an indium-tin-oxide-coated glass instead of a bare glass substrates and point out an interesting scanning electron microscopy imaging artifact when measuring the samples deposited directly on nonconductive substrates. A shrinkage effect is seen due to sample charging, causing the measured dimensions to appear smaller than the physical size of the object.
Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 2013
ABSTRACT Nanostructured dielectric membranes are used in several applications ranging from de Bro... more ABSTRACT Nanostructured dielectric membranes are used in several applications ranging from de Broglie matter-wave optical elements to photonic crystals. Precise pattern transfer and high aspect ratio structures are crucial for many applications. The authors present an improved method for direct patterning on free-standing, dielectric membranes using electron-beam (e-beam) lithography. The method is based on an advanced etchmask that both reduces charging and allows for tuning of the etch mask thickness to support high aspect ratios even for small structures. The authors etched structures as small as 50 nm radius holes in a 150 nm thick membrane and achieved aspect ratios of up to 1.3 for this structure size range. The etch mask thickness can be tuned to achieve the required aspect ratio. The etchmask is composed of a three layer stack consisting of poly(methyl methacrylate), SiO2 and an antireflective coating polymer. Scanning-electron micrographs of membranes produced with the fabrication method are presented.
Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for... more Beams of neutral atoms or molecules at thermal energies are already known as a powerful probe for structural and dynamical analysis of solid surface properties, and in particular characteristics on the nanometer scale. By the implementation of suitable optical ...
Identifying and distinguishing between natural textile fibres is an important task in both archae... more Identifying and distinguishing between natural textile fibres is an important task in both archaeology and criminology. Wool, silk and cotton fibres can readily be distinguished from the textile bast fibres flax, nettle/ramie, hemp and jute. Distinguishing between the bast fibres is, however, not easily done and methods based on surface characteristics, chemical composition and cross section size and shape are not conclusive. A conclusive method based on X-ray microdiffraction exists, but as the method requires the use of a synchrotron it is not readily available. In this paper we present a simple procedure for identifying the above mentioned textile bast fibres. The procedure is based on measuring the fibrillar orientation with polarised light microscopy and detecting the presence of calcium oxalate crystals (CaC2O4) in association with the fibres. To demonstrate the procedure, a series of fibre samples of flax, nettle, ramie, hemp and jute were investigated. The results are presented here. An advantage of the procedure is that only a small amount of fibre material is needed.
Seminal field ionization detection of a supersonic helium beam is reported, including intensity m... more Seminal field ionization detection of a supersonic helium beam is reported, including intensity measurements on a continuous beam and time-of-flight measurements on a chopped beam. Also unique to these experiments is the care with which the field ionization tip was prepared and characterized prior to its use. Comparative measurements on a static helium gas are presented and the effective detection
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Papers by Bodil Holst