ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Surface-state linewidth from scanning tunnelling spectroscopy (1999)

Berndt, R. ; Li, J. ; Schneider, W.D. ; [et al.]

Springer

Applied physics 69 (1999), S. 503-506

add to mindlist on the mindlist

Details

ISSN: 1432-0630

Keywords: PACS: 73.20.At; 61.16.Ch; 72.10.Fk; 73.20.Dx

Source: Springer Online Journal Archives 1860-2000

Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics

Notes: Abstract. The STM can be used to investigate lifetimes of hot holes in a surface state at low temperatures. We analysed dI/dV data from Ag(111) using detailed tunnelling calculations and a simple model and found an electron self-energy of Σ=4.9±0.6 meV. The corresponding lifetime τ= 67±8 fs is considerably higher than those determined by angle-resolved photoemission, although it remains below theoretical predictions. Spatially resolved dI/dV spectra reveal that the lifetime decreases drastically in proximity to defects such as surface steps.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s003390051453

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

The mechanical properties of materials with interconnected cracks and pores (1996)

Hudson, J. A. ; Liu, E. ; Crampin, S.

Oxford, UK : Blackwell Publishing Ltd

Geophysical journal international 124 (1996), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-246X

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geosciences

Notes: This paper studies the effect on the overall properties of a cracked solid of the existence of connections between otherwise isolated cracks and of small-scale porosity within the ‘solid’ material. The intention is to provide effective medium models for the calculation of elastic wave propagation with wavelengths greater than the dimensions of the cracks. The method follows that of earlier papers in which the overall elastic properties are directly related to parameters governing the microstructure, such as crack number density and the mean radius and spacing distance of the cracks. Expressions derived by the method of smoothing are evaluated to second order in the number density of cracks, thereby incorporating crack–crack interactions through both the strain field in the solid and the flow field of fluids in the pores.Flow of interstitial liquids tends to weaken the material; the limit of zero flow is equivalent to isolating the cracks and the limit of free flow is equivalent to dry (gas-filled) cracks. It also introduces additional attenuation. The inclusion of small-scale porosity gives a model of ‘equant porosity’ which is more closely constrained by the details of crack dynamics than earlier models.