Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m)
Abstract
Lattice based kinetic Monte Carlo (KMC) simulations have been used to determine a functional form for the second order adsorption isotherms on two commonly investigated crystal surfaces: the (111) fluorite surface and the (100) perovskite surface which has the same geometric symmetry as the NaCl (100) surface. The functional form is generalized to be applicable to all values of the equilibrium constant by a shift along the pressure axis. Functions have been determined for estimating the pressure at which a desired coverage would be achieved and for estimating the coverage at a certain pressure. The generalized form has been calculated by investigating the surface adsorbate coverage across a range of thermodynamic equilibrium constants that span the range 1026 to 1013. Finally, the equations have been shown to be general for any value of the adsorption equilibrium constant.
 Authors:
 Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Materials Science and Engineering
 Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Materials Science and Engineering; Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Mechanical Engineering
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
 Publication Date:
 Research Org.:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Sponsoring Org.:
 USDOE Laboratory Directed Research and Development (LDRD) Program
 OSTI Identifier:
 1311241
 DOE Contract Number:
 AC0500OR22725
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 145; Journal Issue: 6
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Molecular Adsorption; Dissociative Adsorption; Adsorption Isotherm; Perovskite; Fluorite
Citation Formats
Danielson, Thomas, Hin, Celine, and Savara, Aditya. Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m). United States: N. p., 2016.
Web. doi:10.1063/1.4960508.
Danielson, Thomas, Hin, Celine, & Savara, Aditya. Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m). United States. doi:10.1063/1.4960508.
Danielson, Thomas, Hin, Celine, and Savara, Aditya. Wed .
"Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m)". United States.
doi:10.1063/1.4960508. https://www.osti.gov/servlets/purl/1311241.
@article{osti_1311241,
title = {Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m)},
author = {Danielson, Thomas and Hin, Celine and Savara, Aditya},
abstractNote = {Lattice based kinetic Monte Carlo (KMC) simulations have been used to determine a functional form for the second order adsorption isotherms on two commonly investigated crystal surfaces: the (111) fluorite surface and the (100) perovskite surface which has the same geometric symmetry as the NaCl (100) surface. The functional form is generalized to be applicable to all values of the equilibrium constant by a shift along the pressure axis. Functions have been determined for estimating the pressure at which a desired coverage would be achieved and for estimating the coverage at a certain pressure. The generalized form has been calculated by investigating the surface adsorbate coverage across a range of thermodynamic equilibrium constants that span the range 1026 to 1013. Finally, the equations have been shown to be general for any value of the adsorption equilibrium constant.},
doi = {10.1063/1.4960508},
journal = {Journal of Chemical Physics},
number = 6,
volume = 145,
place = {United States},
year = {Wed Aug 10 00:00:00 EDT 2016},
month = {Wed Aug 10 00:00:00 EDT 2016}
}

Generalized adsorption isotherms for molecular and dissociative adsorption of a polar molecular species on two polar surface geometries: Perovskite (100) (Pm3m) and fluorite (111) (Fm3m)
Lattice based kinetic Monte Carlo simulations have been used to determine a functional form for the second order adsorption isotherms on two commonly investigated crystal surfaces: the (111) fluorite surface and the (100) perovskite surface which has the same geometric symmetry as the NaCl (100) surface. The functional form is generalized to be applicable to all values of the equilibrium constant by a shift along the pressure axis. Functions have been determined for estimating the pressure at which a desired coverage would be achieved and, conversely, for estimating the coverage at a certain pressure. The generalized form has been calculatedmore » 
Molecular ethylene adsorption on Rh(111) and Rh(100): estimation of the CC stretching force constant from the surface vibrational frequencies
Molecular ethylene adsorption on Rh(111) and Rh(100) between 90 and 200 K has been studied by thermal desorption spectroscopy (TDS), lowenergy electron diffraction (LEED), and highresolution electron energy loss spectroscopy (HREELS). The HREEL vibrational spectra for molecularly adsorbed ethylene on these surfaces are interpreted by using the DewarChattDuncanson model for ethylene coordination to metal atom(s); gasphase ethylene and gauche 1,2dibromoethane are used to model the coordination extremes. It is shown that the traditional CH/sub 2/ functional group modes are coupled in adsorbed ethylene and do not adequately describe the normal modes of vibration. However, the CC stretching force constant inmore » 
GaAs (111) and (1'. 2m''. 3m ' '. 2m''. 3m' 1'. 2m''. 3m ' '. 2m''. 3m' 1'. 2m''. 3m ' '. 2m''. 3m' ) surfaces and the GaAs/AlAs (111) heterojunction studied using a local energy density
We use a local energy density {ital scrE}({bold r}) within densityfunctional theory to study GaAs (111) and ({bar 1} {bar 1} {bar 1}) surfaces, and the GaAs/AlAs (111) heterojunction. We use {ital scrE}({bold r}) to calculate the formation enthalpy of a single isolated GaAs (111) and ({bar 1} {bar 1} {bar 1}) surface, which is not possible with the use of conventional totalenergy methods. We are able to address questions related to the stability of these surfaces. Our methods also apply to heterojunctions where we consider GaAs/AlAs (111) as a prototype. We use {ital scrE}({bold r}) to calculate the formationmore »