Surface energies and electronic properties of intermetallic compound B2-AgMg

2019 ◽  
Vol 33 (08) ◽  
pp. 1950097
Author(s):  
Jing-Bo Sun ◽  
Jian-Gang Yao ◽  
Jiang Meng ◽  
Shuping Li ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Surface Energy ◽  
Electronic Properties ◽  
Surface Analysis ◽  
Chemical Potential ◽  
New Method ◽  
Surface Energies ◽  
Surface Models

A new method was used to predict the surface energies of three low-index surfaces for intermetallic compound B2-AgMg. The results show that Ag-terminal and Mg-terminal are the two kinds of surface models for (1 0 0) and (1 1 1) surfaces which are non-stoichiometry. (1 1 0) surface has only one surface terminal, which is stoichiometry, and the smallest surface energy (about [Formula: see text] in three low-index surfaces. The surface energies are related to the chemical potential of Ag and Mg atoms for (1 0 0) and (1 1 1) surfaces, but it is of no concern to this factor for stoichiometry (1 1 0) surface. Analysis of electronic properties is coincident with the calculated surface energies.

Tuning the surface energies in a family of poly-3-alkylthiophenes bearing hydrophilic side-chains synthesized via direct arylation polymerization (DArP)

2021 ◽  
Author(s):  
Alexander Schmitt ◽  
Sanket Samal ◽  
Barry C. Thompson
Keyword(s):  
Surface Energy ◽  
Electronic Properties ◽  
Functional Groups ◽  
Functional Group ◽  
Side Chains ◽  
Direct Arylation ◽  
Surface Energies ◽  
Direct Arylation Polymerization

A family of Poly(3-alkylthiophene) copolymers bearing different functional groups was synthesized via direct arylation polymerization and the functional group impact on surface energy, crystallinity, and electronic properties was investigated.

scholarly journals Evolution Mechanism of Metallic Dioxide MO2 (M = Mn, Ti) from Nanorods to Bulk Crystal: First-Principles Research

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Pengsen Zhao ◽  
Guifa Li ◽  
Bingtian Li ◽  
Haizhong Zheng ◽  
Shiqiang Lu ◽  
...  
Keyword(s):  
Surface Energy ◽  
Electronic Properties ◽  
Surface Effect ◽  
Mulliken Charge ◽  
Mulliken Population ◽  
Evolution Mechanism ◽  
Surface Energies ◽  
Surface Areas ◽  
Nanometer Materials ◽  
Intrinsic Mechanism

Using first-principle calculations, the surface energy, cohesive energy, and electronic properties of α-MnO2 and rutile TiO2 nanorods and microfacets were investigated and clarified to, in the first instance, determine the evolution mechanism. The results show that the surface energies of α-MnO2 nanorods and microfacets conform to function 1.0401 Jm−2 + N × 0.608 Jm−2, while the surface energies of the rutile TiO2 nanorods and microfacets are governed by a 1.0102 × 1.1997 rule. Their electronic properties, such as the Mulliken population and Mulliken charge, can only be normalized by their surface areas to attain a linear function. Meanwhile, the surface energy of α-MnO2 with the nanostructure closely conforms to the function for normalized Mulliken population and Mulliken charge as f(x)=102.9×x+0.101 with an R2 value of 0.995. Thus, our research into the evolution mechanism affecting the surface effect of nanometer materials will be useful for investigating the intrinsic mechanism of the nanometer effect and doping process of metallic dioxide catalysts.

scholarly journals Vertical Orientation of Liquid Crystal on 4-n-Alkyloxyphenoxymethyl-Substituted Polystyrene Containing Liquid Crystal Precursor

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 736
Author(s):  
Kyutae Seo ◽  
Hyo Kang
Keyword(s):  
Molecular Structure ◽  
Liquid Crystal ◽  
Surface Energy ◽  
Polymer Films ◽  
Ultraviolet Irradiation ◽  
Molar Fraction ◽  
Side Chain ◽  
Polymer Modification ◽  
Vertical Orientation ◽  
Surface Energies

We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4-n-butyloxyphenol (PBOP), 4-n-hexyloxyphenol (PHOP), and 4-n-octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40–100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m2. Good alignment stabilities were observed at 150 °C and 20 J/cm2 of ultraviolet irradiation for LC cells fabricated with PEOP film.

Application of a Novel Modified Electrode Based on NaY-Encapsulated Co(PAN) Complex

2008 ◽  
Vol 587-588 ◽  
pp. 109-113
Author(s):  
C. Teixeira ◽  
P. Parpot ◽  
Isabel Neves ◽  
António Maurício C. Fonseca
Keyword(s):  
Cyclic Voltammetry ◽  
Chemical Analysis ◽  
Aqueous Medium ◽  
Surface Analysis ◽  
Modified Electrode ◽  
Modified Electrodes ◽  
Redox Properties ◽  
New Method ◽  
Y Zeolite

CoPAN complex has been entrapped in the supercages of Y zeolite and the redox properties of this zeolite-encapsulated complex were investigated by cyclic voltammetry with a new method for the preparation of carbon toray-zeolite-modified electrode. Formation of the CoPAN complex was ascertained by surface analysis (SEM, XRD), chemical analysis (CA), spectroscopy methods (FTIR and UV/vis) and cyclic voltammetry in aqueous medium with zeolite-modified electrodes. The cyclic voltammetry studies obtained with a zeolite-modified electrode shows evidence for electroactivity restricted to boundary associated CoPAN complex.

SURFACE ENERGY ENGINEERING OF Cu SURFACE BY STRAIN: FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 20 (06) ◽  
pp. 1350054 ◽  
Author(s):  
L. HE ◽  
Y. W. LIU ◽  
W. J. TONG ◽  
J. G. LIN ◽  
X. F. WANG
Keyword(s):  
Surface Energy ◽  
First Principles ◽  
Strain Distribution ◽  
First Principles Calculations ◽  
Surface Energies ◽  
Energy Engineering

Surface energies of strained Cu surfaces were studied systematically using first-principles methods. Results showed that the strain-stabilization of Cu surface was anisotropic and strongly related to the strain distribution. This strain-induced approach could be used as an effective way to engineer the surface energies of metals.

Welding of Fe-Al Intermetallic Compound and Steel by SPS Technology

2012 ◽  
Vol 581-582 ◽  
pp. 582-585
Author(s):  
Guo Dong Zhang ◽  
Ya Dong Xiao ◽  
Nian Liu ◽  
Min Hong
Keyword(s):  
Intermetallic Compound ◽  
Base Metal ◽  
Heat Affected Zone ◽  
High Strength Steel ◽  
Chemical Potential ◽  
High Strength ◽  
Micro Hardness ◽  
Axial Pressure ◽  
Welding Joint ◽  
Short Period

The welding between Fe-Al intermetallic compound and high-strength steel was done via SPS technology. Microstructure, elements concentration and micro-hardness of welding joint were examined. The results indicated that there was no obvious welding heat-affected zone in both Fe-Al intermetallic compound and high-strength steel. The HAZ microstructures of high-strength steel were mainly martensite. In Fe-Al intermetallic compound, the grain size of heat-affected zone was larger than that of base metal and the density of heat-affected zone was lower than that of base metal. Besides, the grains of base metal had deformation phenomena. The welding joint had steady performance and the connection was reliable. Under the influence of chemical potential differences, unidirectional impulses discharge current and axial pressure, elements diffused perfectly in a short period of time.

scholarly journals Surface energies emerging in a microscopic, two-dimensional two-well problem

2017 ◽  
Vol 147 (5) ◽  
pp. 1041-1089 ◽  
Author(s):  
Georgy Kitavtsev ◽  
Stephan Luckhaus ◽  
Angkana Rüland
Keyword(s):  
Surface Energy ◽  
Two Dimensional ◽  
Direct Control ◽  
First Order ◽  
Surface Energies ◽  
Energy Scaling ◽  
Continuous Analogue ◽  
Dimensional Shape ◽  
Set Up ◽  
Microscopic Modelling

In this paper we are interested in the microscopic modelling of a two-dimensional two-well problem that arises from the square-to-rectangular transformation in (two-dimensional) shape-memory materials. In this discrete set-up, we focus on the surface energy scaling regime and further analyse the Hamiltonian that was introduced by Kitavtsev et al. in 2015. It turns out that this class of Hamiltonians allows for a direct control of the discrete second-order gradients and for a one-sided comparison with a two-dimensional spin system. Using this and relying on the ideas of Conti and Schweizer, which were developed for a continuous analogue of the model under consideration, we derive a (first-order) continuum limit. This shows the emergence of surface energy in the form of a sharp-interface limiting model as well the explicit structure of the minimizers to the latter.

scholarly journals Thermodynamics of the Atomic Distribution in Pt3Pd2, Pt2Pd3 and their Corresponding (111) Surfaces

2021 ◽  
Vol 74 ◽  
Author(s):  
Kyle Meerholz ◽  
David Santos-Carballal ◽  
Umberto Terranova ◽  
Anzel Falch ◽  
Cornelia G.C.E. van Sittert ◽  
...  
Keyword(s):  
Solid State ◽  
Bimetallic Catalysts ◽  
Computational Study ◽  
Interatomic Potentials ◽  
Site Occupation ◽  
Surface Energies ◽  
General Utility ◽  
Production Of Hydrogen ◽  
Surface Models ◽  
State Models

ABSTRACT In this study, we have developed solid-state models of platinum and palladium bimetallic catalysts, Pt3Pd2 and Pt2Pd3, which are rapidly thermally annealed at 800 °C. These models were constructed by determining all the unique atomic configurations in a 2x2x1 supercell, using the program Site-Occupation Disorder (SOD), and optimized with the General Utility Lattice Program (GULP) using Sutton-Chen interatomic potentials. Each catalyst had 101 unique bulk models that were developed into surface models, which were constructed using the two-region surface technique before the surface energies were determined. The planes and compositions with lowest surface energies were chosen as the representative models for the surface structure of the bimetallic catalysts. These representative models will now be used in a computational study of the HyS process for the production of hydrogen. Keywords: HyS process, platinum, palladium, solid-state, catalyst, Site-Occupation Disorder.

Fiber Blending Irregularities in Cross Sections and on Yarn Surfaces in Relation to Yarn Properties

1988 ◽  
Vol 58 (5) ◽  
pp. 291-298 ◽  
Author(s):  
Izabella Krucińnska
Keyword(s):  
Surface Analysis ◽  
Cross Sections ◽  
Original Method ◽  
New Method ◽  
Cross Sectional ◽  
Yarn Properties ◽  
Yarn Surface ◽  
Fiber Blending

An analysis of fiber blending irregularities is presented in relation to the disturbances of blend yarn properties resulting from these phenomena. Fiber blending irregularities were assessed using the original method of yarn surface analysis and a new method of yarn cross-sectional division. These methods correctly reflect the disturbances in the mechanical and aesthetic yarn properties resulting from non-uniform mixing of constituent fibers.

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