Convergence of the gradient expansion in metallic surface-energy calculations

1977 ◽  
Vol 15 (2) ◽  
pp. 580-583 ◽  
Author(s):  
Mark Rasolt ◽  
J. Shy-Yih Wang ◽  
L. M. Kahn
Keyword(s):  
Surface Energy ◽  
Metallic Surface ◽  
Gradient Expansion ◽  
Energy Calculations

The annealed (0001) α-alumina surface and its influence on thin-film growth

1995 ◽  
Vol 53 ◽  
pp. 336-337
Author(s):  
Michael W. Bench ◽  
Paul G. Kotula ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Surface Energy ◽  
Film Growth ◽  
Thin Film Growth ◽  
Energy Calculations ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Low Energy Electron ◽  
Surface Nature

The growth of semiconductors, superconductors, metals, and other insulators has been investigated using alumina substrates in a variety of orientations. The surface state of the alumina (for example surface reconstruction and step nature) can be expected to affect the growth nature and quality of the epilayers. As such, the surface nature has been studied using a number of techniques including low energy electron diffraction (LEED), reflection electron microscopy (REM), transmission electron microscopy (TEM), molecular dynamics computer simulations, and also by theoretical surface energy calculations. In the (0001) orientation, the bulk alumina lattice can be thought of as a layered structure with A1-A1-O stacking. This gives three possible terminations of the bulk alumina lattice, with theoretical surface energy calculations suggesting that termination should occur between the Al layers. Thus, the lattice often has been described as being made up of layers of (Al-O-Al) unit stacking sequences. There is a 180° rotation in the surface symmetry of successive layers and a total of six layers are required to form the alumina unit cell.

scholarly journals Towards a standardized setup for surface energy calculations

2017 ◽  
Vol 95 (8) ◽  
Author(s):  
Jakub W. Kaminski ◽  
Peter Kratzer ◽  
Christian Ratsch
Keyword(s):  
Surface Energy ◽  
Energy Calculations

Two-dimensional MOF-based Liquid Marbles: Surface Energy Calculations and Efficient Oil-Water Separation Using a ZIF-9-III@PVDF Membrane

2021 ◽  
Author(s):  
Jayaramulu Kolleboyina ◽  
HANEESH SAINI ◽  
Parashuram Kallem ◽  
Eva Otyepková ◽  
Florian Geyer ◽  
...  
Keyword(s):  
Surface Energy ◽  
Two Dimensional ◽  
Water Separation ◽  
Pvdf Membrane ◽  
Energy Calculations ◽  
Liquid Marbles ◽  
Droplet Form ◽  
Oil Water Separation ◽  
Oil Water ◽  
Aqueous Droplet

Superhydrophobic MOF-nanosheets assembled on the outside of an aqueous droplet form ‘liquid marbles’. A facile mechanochemical-based synthesis followed by ultrasonication was used to prepare two-dimensional superhydrophobic-oleophilic MOF nanosheets of a...

scholarly journals Adhesive interactions of geckos with wet and dry fluoropolymer substrates

2015 ◽  
Vol 12 (108) ◽  
pp. 20150464 ◽  
Author(s):  
Alyssa Y. Stark ◽  
Daniel M. Dryden ◽  
Jeffrey Olderman ◽  
Kelly A. Peterson ◽  
Peter H. Niewiarowski ◽  
...  
Keyword(s):  
Surface Energy ◽  
Interfacial Energy ◽  
Substrate Surface ◽  
Energy Calculations ◽  
Bioinspired Design ◽  
Interfacial Energies ◽  
Normal Adhesion ◽  
Adhesive Interactions ◽  
Low Shear

Fluorinated substrates like Teflon ® (poly(tetrafluoroethylene); PTFE) are well known for their role in creating non-stick surfaces. We showed previously that even geckos, which can stick to most surfaces under a wide variety of conditions, slip on PTFE. Surprisingly, however, geckos can stick reasonably well to PTFE if it is wet. In an effort to explain this effect, we have turned our attention to the role of substrate surface energy and roughness when shear adhesion occurs in media other than air. In this study, we removed the roughness component inherent to commercially available PTFE and tested geckos on relatively smooth wet and dry fluoropolymer substrates. We found that roughness had very little effect on shear adhesion in air or in water and that the level of fluorination was most important for shear adhesion, particularly in air. Surface energy calculations of the two fluorinated substrates and one control substrate using the Tabor–Winterton approximation and the Young–Dupré equation were used to determine the interfacial energy of the substrates. Using these interfacial energies we estimated the ratio of wet and dry normal adhesion for geckos clinging to the three substrates. Consistent with the results for rough PTFE, our predictions show a qualitative trend in shear adhesion based on fluorination, and the quantitative experimental differences highlight the unusually low shear adhesion of geckos on dry smooth fluorinated substrates, which is not captured by surface energy calculations. Our work has implications for bioinspired design of synthetics that can preferentially stick in water but not in air.

Brittle fracture toughnesses of GaN and AlN from first-principles surface-energy calculations

2015 ◽  
Vol 106 (21) ◽  
pp. 212103 ◽  
Author(s):  
C. E. Dreyer ◽  
A. Janotti ◽  
C. G. Van de Walle
Keyword(s):  
Brittle Fracture ◽  
Surface Energy ◽  
First Principles ◽  
Energy Calculations

Lattice potentials as an instrument in crystal chemistry. III. Applications to crystal surfaces1

1997 ◽  
Vol 212 (8) ◽  
Author(s):  
H. P. Beck ◽  
T. Beyer
Keyword(s):  
Surface Energy ◽  
Crystal Chemistry ◽  
Surface Potential ◽  
Surface Effects ◽  
Crystal Surfaces ◽  
Energy Calculations ◽  
Lattice Potential ◽  
Adsorption Phenomena ◽  
Specific Part ◽  
Active Centres

AbstractSome applications of surface potential and MAPSE (Madelung Part of Surface Energy) calculations are presented. MAPSE is a useful tool for the prediction of crystal morphologies and the terminating ion layer in crystal, surfaces. The surface specific part of a lattice potential, called epi-potential can be used to analyse the range of surface effects and to study the potential topology in epi-potential maps. These maps of crystal surfaces show the positions of the next one or two missing ion layers above the surface as active centres for reactions and adsorption phenomena.We present here calculations for NaCl, CaF

Bond-Energy and Surface-Energy Calculations in Metals

2010 ◽  
Vol 87 (6) ◽  
pp. 608-612 ◽  
Author(s):  
James G. Eberhart ◽  
Steve Horner
Keyword(s):  
Surface Energy ◽  
Bond Energy ◽  
Energy Calculations
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