Density Profiles for a Model of Localized Site Adsorption of a Dimerizing Fluid on Crystalline Surfaces. Integral Equation Study

1996 ◽  
Vol 100 (14) ◽  
pp. 5941-5948 ◽  
Author(s):  
Andrij Trokhymchuk ◽  
Orest Pizio ◽  
Douglas Henderson ◽  
Stefan Sokołowski
Keyword(s):  
Integral Equation ◽  
Density Profiles ◽  
Crystalline Surfaces

DENSITY PROFILES OF A HARD GAUSSIAN OVERLAP FLUID BETWEEN HARD WALLS

2005 ◽  
Vol 19 (10) ◽  
pp. 1717-1729 ◽  
Author(s):  
M. MORADI ◽  
A. AVAZPOUR
Keyword(s):  
Density Functional Theory ◽  
Integral Equation ◽  
Correlation Function ◽  
Density Functional ◽  
Direct Correlation Function ◽  
Hard Wall ◽  
Density Profiles ◽  
Functional Theory ◽  
Orientation Model ◽  
The Density Functional Theory

The density profiles of a hard Gaussian overlap (HGO) fluid confined in between hard walls and in contact with a hard wall are studied using the density functional theory. The hyper-netted chain (HNC) approximation is used to find the coupled integral equations for the density profiles. The restricted orientation model (ROM) is used. The required homogeneous direct correlation function (DCF) is obtained by solving Ornstein–Zernike (OZ) integral equation numerically, using the Precus–Yevick (PY) approximation and the procedure mentioned by Letz and Latz [Phys. Rev.E60, 5865 (1999)]. We also obtained the DCF of hard ellipsoidal (HE) fluid by using the modified closest approach introduced by Rickayzen [Mol. Phys.68, 903 (1989)]. For both HGO and HE, we calculate the density profiles of molecules parallel and perpendicular to the walls and we compare the results. The calculations are performed for various values of packing fractions of the fluid and various molecular elongations. For moderate elongations, k≤3, the results for HGO and HE are almost the same, especially for the density profile of the molecules parallel to the walls but for k=5 there are some discrepancies between the results, in particular for the density profiles of the molecules perpendicular to the walls.

High Resolution Low Loss Microscopy of Crystalline Surfaces

1980 ◽  
Vol 38 ◽  
pp. 162-163
Author(s):  
William Krakow ◽  
Alec N. Broers
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Surface Topography ◽  
Secondary Electron ◽  
Objective Lens ◽  
Surface Imaging ◽  
Low Loss ◽  
Fine Grained ◽  
Scanning Electron ◽  
Crystalline Surfaces

Low-loss scanning electron microscopy can be used to investigate the surface topography of solid specimens and provides enhanced image contrast over secondary electron images. A high resolution-condenser objective lens has allowed the low-loss technique to resolve separations of Au nucleii of 50Å and smaller dimensions of 25Å in samples coated with a fine grained carbon-Au-palladium layer. An estimate of the surface topography of fine grained vapor deposited materials (20 - 100Å) and the surface topography of underlying single crystal Si in the 1000 - 2000Å range has also been investigated. Surface imaging has also been performed on single crystals using diffracted electrons scattered through 10−2 rad in a conventional TEM. However, severe tilting of the specimen is required which degrades the resolution 15 to 100 fold due to image forshortening.

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