ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Digitale Medien

Sample manipulator for Auger angular dependence studies (1986)

Barnard, W. O. ; Snyman, H. C. ; Auret, F. D.

[S.l.] : American Institute of Physics (AIP)

Review of Scientific Instruments 57 (1986), S. 2892-2893

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7623

Quelle: AIP Digital Archive

Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik

Notizen: A modification to a commercial sample manipulator is described by which the angle between the incoming beam direction and the normal of the sample, as well as the angle of rotation about the normal, can be changed by 60° and 360°, respectively, from the outside of an UHV analysis chamber.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.1139011

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

2

Digitale Medien

Electrical characterization of neutron irradiation induced defects in undoped epitaxially grown n-GaAs (1993)

Auret, F. D. ; Goodman, S. A. ; Myburg, G. ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 74 (1993), S. 4339-4342

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: Undoped n-GaAs, grown by organometallic vapor phase epitaxy, was irradiated with neutrons from a clinical p(66)/Be(40) source for a range of fluences. Deep level transient spectroscopy (DLTS), employing Pd Schottky barrier diodes, indicated that four electron traps, En1, En2, En4, and En5, with energy levels at 0.04, 0.14, 0.36, and 0.66 eV, respectively, below the conduction band were created during neutron radiation. Their introduction rates varied from 1 cm−1 for the En1 to 11 cm−1 for the En5. It was found that the En1, En2, and En4 defects have DLTS "signatures'' similar to the E1, E2, and E3 point defects introduced during high energy electron irradiation, indicating their point defect nature. The En5 has a very large capture cross section, its emission rate exhibits a strong electric field dependence, and there are indications that it has a band-like energy distribution, that results in a broad DLTS peak. We speculate that this trap is related to the presence of extended defects in the neutron irradiated GaAs.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.354399

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

3

Digitale Medien

Comparison between ruthenium-based and other ohmic contact systems to p-type GaAs (1992)

Barnard, W. O. ; Myburg, G. ; Auret, F. D.

Woodbury, NY : American Institute of Physics (AIP)

Applied Physics Letters 61 (1992), S. 1933-1935

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1077-3118

Quelle: AIP Digital Archive

Thema: Physik

Notizen: A conventional furnace annealed Ru/Au ohmic contact system on p-GaAs has been investigated. Electrical and morphological characteristics of this contact system were compared with other systems such as Cr/Au, Ti/Pt, and Mn/Au. The Ru/Au contact system has been shown to have superior surface morphology and a comparable specific contact resistance value, even after annealing at 485 °C. The advantages of utilizing Ru as contact material to GaAs are that it forms high quality, thermally stable Schottky contacts to n-GaAs and thermally stable ohmic contacts with low specific contact resistance to p-GaAs. This dual nature of Ru contacts to GaAs makes them extremely important for future use in devices such as heterojunction bipolar transistors (HBTs) and solid state lasers.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.108493

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

4

Digitale Medien

Determination of trace quantities of dimethyl sulfide in aqueous solutions (1983)

Andreae, M. O. ; Barnard, W. R.

s.l. : American Chemical Society

Analytical chemistry 55 (1983), S. 608-612

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1520-6882

Quelle: ACS Legacy Archives

Thema: Chemie und Pharmazie

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1021/ac00255a006

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

5

Digitale Medien

Corrosion behaviour of duplex stainless steels containing minor ruthenium additions in reducing acid media (1996)

Potgieter, J. H. ; Barnard, W. O. ; Myburg, G. ; [weitere]

Springer

Journal of applied electrochemistry 26 (1996), S. 1103-1110

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8838

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik

Notizen: Abstract The dissolution behaviour, as well as the time, potential and concentration dependence of HSO − 4 SO 2t- 4 and Cl− accumulations measured by an in situ radiotracer method on surface oxide-layers of duplex stainless steels containing various amounts of ruthenium as additive are presented and discussed. Several independent techniques, such as mass loss tests, potentiodynamic responses, radiotracer and ICP methods, were used to characterize the complex features of the passivation phenomena of steels modified with ruthenium. The experimental results reveal that the interaction of bisulfate/sulfate ions with passive oxide layer is stronger than those of chloride ions on the stainless steels studied. Both the extent and the strong character of bisulfate/sulfate accumulation are more likely related to the redistribution of the main alloying components (Cr, Ni, Mo) as well as the Ru in the surface oxide-film formed on steels passivated spontaneously in dilute HCl and H2SO4. It is found that the ruthenium additions to the base duplex stainless steel significantly increase the corrosion resistance in reducing acid environments. There is evidence of anodic inhibition and this seems to be responsible for the observed increased corrosion resistance of the duplex stainless steels with small ruthenium additions.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00243734

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

6

Digitale Medien

AES and SIMS investigations of the oxide films on Fe-40Cr-Ru alloys (1992)

Tjong, S. C. ; Barnard, W. O. ; Malherbe, J. B.

Springer

Journal of materials science 27 (1992), S. 1818-1826

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-4803

Quelle: Springer Online Journal Archives 1860-2000

Thema: Maschinenbau

Notizen: Abstract Auger and SIMS depth profiling have been used to investigate the effect of ruthenium addition on the oxidation behaviour of the Fe-40Cr-Ru alloys oxidized in air at 500 °C. Auger results revealed that the oxide films formed on the Fe-40Cr-Ru alloys consisted of a thin iron oxide external layer and a chromium-rich internal layer. Ruthenium was not found in these oxide layers. Secondary ion mass spectrometry measurements also indicated a thin Fe+-rich film as an outer layer with a predominantly chromium oxide in the internal layer of the film. Furthermore, ruthenium was incorporated in the entire oxide film and promoted the formation of a thin compact film.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01107209

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

7

Digitale Medien

Alkaline materials flux from unpaved roads: Source strength, chemistry and potential for acid rain neutralization (1986)

Barnard, W. R. ; Stensland, Gary J. ; Gatz, Donald F.

Springer

Water, air & soil pollution 30 (1986), S. 285-293

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-2932

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik

Notizen: Abstract This paper presents data on the alkaline element chemistry of unpaved road surface materials and the potential flux of these elements into the atmosphere. Additionally, we discuss the potential acid neutralizing capacity of unpaved road surface materials in precipitation. The relative contribution of unpaved roads to the total open source flux of alkaline materials is also examined. Preliminary calculations indicate that unpaved roads contribute more than 90% of all open source Ca and Mg in 37 and 33 of the 48 contiguous states, respectively.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00305199

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

8

Digitale Medien

The Characterizing of Particles by the Manner in which they break (1985)

Barnard, W. John ; Bull, Frederick A.

Weinheim : Wiley-Blackwell

Particle and Particle Systems Characterization 2 (1985), S. 25-30

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0934-0866

Schlagwort(e): Chemistry ; Industrial Chemistry and Chemical Engineering

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Maschinenbau , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung

Notizen: A modified drop-shatter test apparatus was used to study the primary breakage of particles of two solid fuels. In this apparatus many particles could be subjected to just one impact under known conditions.About 100000 particles of each fuel, sorted by size and shape into eight separate groups, were dropped from four different heights and the fragments thus formed were sifted to determine their size distributions, that is the experimental breakage functions.The interior of particles, of regular or irregular shape, fails under tension and the resulting fragmentation is due to stress-activated volume flaws which give rise to coarse fragments whose distribution can be represented by a theoretical breakage function of the form \documentclass{article}\pagestyle{empty}\begin{document}$$ B(z) = \mathop \Sigma \limits_{{\rm \gamma = 1}}^\infty \left[ {\frac{{\lambda \cdot e^{ - \lambda } }}{{{\rm \gamma !(1 - }e^{ - \lambda } )}} \cdot \left\{ {1 - (1 + {\rm \gamma }z^3 )(1 - z^3 )^{\rm \gamma } } \right\}} \right] $$\end{document} where z is the relative size of the fragments and γ is the number of stress-activated volume flaws per particle.The average values of γ, given by μγ = λ/(1 - e-λ), ranged from about one to five, corresponding to the formation of two to six coarse fragments per broken particle.The probability of breakage was log-normally related to μγ.

Zusätzliches Material: 8 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/ppsc.19850020105

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

9

Digitale Medien

Preferential sputtering of GaAs (1992)

Malherbe, J. B. ; Barnard, W. O. ; Strydom, I. Le R. ; [weitere]

Chichester [u.a.] : Wiley-Blackwell

Surface and Interface Analysis 18 (1992), S. 491-495

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0142-2421

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Physik

Notizen: Low-energy (0.65-3 keV) Ar+ ions were used to sputter (100) and (110) GaAs. Preferential sputtering effects were investigated by means of Auger electron spectroscopy. The results show that the equilibrium sputtered surface composition on both surfaces is depleted in As. No sample orientation effects were observed. However, the equilibrium compositions of the sputtered surfaces become increasingly Ga-enriched by increasing the energy of the bombarding ions. The sputtered surface composition is independent of the angle of incidence of the bombarding Ar+ ions. For the different experimental conditions, the mean final surface compositions varied from GaAs0.89 to GaAs0.69. These values are in broad agreement with other reported AES studies. This agreement is probably due to the fact that the sputtered surface composition is independent of the angle of incidence of the ions on the GaAs sample.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/sia.740180706

Permalink