Recent Developments

Güntherodt, H.‐J.; Wiesendanger, R.

doi:10.1007/978-3-642-79255-7_9

Cited by 3 publications

(3 citation statements)

References 180 publications

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“…While the process without illumination causes the growth of some dispersed particles in the range 50-150 nm (figure 4 Those charge carriers which emerge from illumination and are created in the sub-surface space charge region experience a strong electric field (an electrostatic potential barrier exists in the space charge region) which tends to separate the electron and the hole. As the bands bend downwards for p-type material, the electrons move toward the surface and the holes move away [34]. Now these electrons can improve the electroless process.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Pd nanoparticle dispersed over porous silicon as a hydrogen sensor

Rahimi

zad

2007

J. Phys. D: Appl. Phys.

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Porous silicon samples were obtained by the electrochemical method and were impregnated with Pd by the electroless process. X-ray photoelectron spectroscopy illustrated that the surface of the samples is oxidized during the palladium deposition. Scanning electron microscopy showed how factors such as morphology and pre-oxidations of porous samples and the plating parameters including Pd-salt concentration, HCl concentration, temperature of the electroless solution and the time of process affect the growth and nucleation of Pd particles. Observations demonstrated that the illumination-assisted process on p-type samples has a drastic effect on the growth of palladium. Hydrogen sensing of these samples, which works on the basis of change in the Schottky barrier between the silicon and the palladium interface, was tested. Variations of the electrical resistance in the presence of diluted hydrogen at room temperature revealed that the best samples can sense hydrogen at levels down to several thousand ppm. This value is far below the flammability limit of hydrogen gas. In addition, the best samples have a very good selectivity to hydrogen.

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Section: Resultsmentioning

confidence: 99%

Characterization of Pd nanoparticle dispersed over porous silicon as a hydrogen sensor

Rahimi

zad

2007

J. Phys. D: Appl. Phys.

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“…Distortions caused by dynamic effects can be seen in figure 2, which shows experimental images of highly oriented pyrolytic graphite (HOPG), a standard sample used in the study of STMs. It is noted that the HOPG image has a hexagonal lattice structure with a regular atomic separation of 2.46 Å [21], as seen in figure 2(a). Furthermore, the positions of carbon atoms on the surface of the HOPG sample do not change with respect to STM-probe position and are relatively insensitive to variations in operating conditions such as temperature [11,22].…”

Section: Distortions In Stm Images Caused By Dynamic Effectsmentioning

confidence: 95%

Image-based compensation of dynamic effects in scanning tunnelling microscopes

Devasia

2005

Nanotechnology

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In this paper, we address the problems associated with the identification and compensation of adverse dynamic effects (magnitude and phase distortions) that limit the operating speed in currently available scanning tunnelling microscopes (STMs). To minimize errors caused by dynamic effects, current STM systems are operated at relatively low speeds (scan frequencies) when compared to the first resonant frequency of the system. Low operating speed limits the temporal resolution of STMs, which in turn limits the STM’s ability to observe fast surface phenomena, and reduces the throughput of STM-based applications such as nanofabrication. Our main contribution is the development of an image-based approach that exploits the extant imaging capabilities of the STM to identify and compensate for errors caused by unwanted dynamic effects, thereby enabling high-speed STM operation. The proposed image-based method is illustrated by applying it to an experimental STM.

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“…In particular, the employment of scanning probe microscopies (SPM) has extended our knowledge significantly on the respective thin film properties, such as structure, morphology and growth kinetics, during the past decades [12][13][14]. The use of refractory (W, Mo, Re) or at least high-melting point metal surfaces (Pt, Ir, Rh, Ru) as substrates for thin film deposition has the advantage that the deposited material can be conveniently removed by thermal desorption.…”

Section: Introductionmentioning

confidence: 99%

Interaction of copper with the rhenium$(1 0\bar {1}0)$ surface

Przyrembel

Messahel²,

Christmann

2013

J. Phys.: Condens. Matter

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We have studied the adsorption of copper on the clean Re(101[overline]0) surface between 300 and 900 K by means of low- and medium-energy electron diffraction (LEED and MEED) and temperature-programmed thermal desorption (TPD). The persistence of a (1 × 1) LEED pattern during Cu deposition suggests the formation of pseudomorphic Cu islands. Accordingly, the intensity-voltage behaviour of the (1 × 1) LEED beams can be quantitatively superimposed by the coverage-weighed fractions of the I(V)-curves of uncovered Re areas and of Cu-covered (1 × 1) islands. At a coverage of 1.625 × 10(19) Cu atoms m(-2) dynamical LEED I(V) calculations suggest a full hcp-oriented Cu bilayer (BL). Within this first BL, Cu wets the Re surface completely, while all following layers exhibit remnant roughness due to small Cu nuclei, as confirmed by in situ grazing-incidence MEED experiments. The completion of the first BL coincides with the saturation of a single β TPD state at 1180 K, whilst higher coverages produce an additional zero-order α state, which peaks at 1080 K at 2.6 BL. The energy of desorption rises from 320 kJ mol(-1) at small coverages to ~360 kJ mol(-1) for a bilayer Cu film, pointing to attractive lateral Cu-Cu interactions. An analysis of the leading edge of the multilayer α state yields a desorption energy of ~305 kJ mol(-1), somewhat lower than the sublimation enthalpy of bulk Cu. Our data are discussed and compared with previous results on related systems.

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Recent Developments

Cited by 3 publications

References 180 publications

Characterization of Pd nanoparticle dispersed over porous silicon as a hydrogen sensor

Characterization of Pd nanoparticle dispersed over porous silicon as a hydrogen sensor

Image-based compensation of dynamic effects in scanning tunnelling microscopes

Interaction of copper with the rhenium$(1 0\bar {1}0)$ surface

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