253 research outputs found
Underpotential deposition of Cu on Au(111) in sulfate-containing electrolytes: a theoretical and experimental study
We study the underpotential deposition of Cu on single-crystal Au(111)
electrodes in sulfate-containing electrolytes by a combination of computational
statistical-mechanics based lattice-gas modeling and experiments. The
experimental methods are in situ cyclic voltammetry and coulometry and ex situ
Auger electron spectroscopy and low-energy electron diffraction. The
experimentally obtained voltammetric current and charge densities and adsorbate
coverages are compared with the predictions of a two-component lattice-gas
model for the coadsorption of Cu and sulfate. This model includes effective,
lateral interactions out to fourth-nearest neighbors. Using group-theoretical
ground-state calculations and Monte Carlo simulations, we estimate effective
electrovalences and lateral adsorbate--adsorbate interactions so as to obtain
overall agreement with experiments, including both our own and those of other
groups. In agreement with earlier work, we find a mixed R3xR3 phase consisting
of 2/3 monolayer Cu and 1/3 monolayer sulfate at intermediate electrode
potentials, delimited by phase transitions at both higher and lower potentials.
Our approach provides estimates of the effective electrovalences and lateral
interaction energies, which cannot yet be calculated by first-principles
methods.Comment: 36 pages, 14 Postscript figures are in uufiles for
Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes
Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium,
and thirty-one terbium isotopes have been observed and the discovery of these
isotopes is discussed here. For each isotope a brief synopsis of the first
refereed publication, including the production and identification method, is
presented.Comment: To be published in At. Data Nucl. Data Table
Discovery of the Isotopes with 11 <= Z <= 19
A total of 194 isotopes with 11 Z 19 have been identified to
date. The discovery of these isotopes which includes the observation of unbound
nuclei, is discussed. For each isotope a brief summary of the first refereed
publication, including the production and identification method, is presented.Comment: to be pubslihed in At. Data Nucl. Data Table
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