Results 261 to 270 of about 1,314,344 (348)

Cross-sectional atomic force imaging of semiconductor heterostructures

Materials Science and Engineering: B, 1996
Abstract We performed imaging of semiconductor heterostructures, in particular GaAs-AlGaAs quantum wells and quantum wires, by atomic force microscopy (AFM) of the cleaved edge of the samples. We used two methods to transform the alloy composition into height differences, measurable by AFM: natural oxidation and selective etching.
B Dwir, F Reinhardt, G Biasiol, E Kapon
openaire   +2 more sources

On atomic photoionization cross section calculation

Physics Letters A, 1969
Abstract Essential peculiarities of the Hartree-Fock photoionization cross section are discussed: 1) the choice of the operator of interaction with the electromagnetic field, 2) sum rules and 3) the influence of various modifications of the self-consistent field.
M.Ya. Amusia, N.A. Cherepkov, L.V. Chernysheva, S.I. Sheftel   +3 more
openaire   +1 more source

Cross sections for electron scattering by atomic potassium

Physical Review A, 1992
Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4\ensuremath{\le}E\ensuremath{\le}200 eV. Configuration-interaction target wave functions that take
, Msezane, , Awuah, , Hiamang, , Allotey
openaire   +2 more sources

Cross sections for the alkali atom-Br2 reactions

The Journal of Chemical Physics, 1973
The reaction cross sections of alkali metal atoms with bromine molecules have been obtained by direct measurements of alkali atom decay rates. The alkali atoms were produced in the presence of a known amount of bromine molecules by photodissociating the bromide of the particular alkali atom with a short pulse of uv light.
J. Maya, P. Davidovits
openaire   +1 more source

Electron Ionization Cross Sections for Atomic Subshells

Microscopy and Microanalysis, 2003
Ionization of atoms is the first step in many analytical procedures. The cross section for ionizing a particular atomic shell is essential for calculating the magnitude of analytical signals. Calculations using atomic wave functions for various shells of all elements relevant for X-ray microanalysis over a range of electron energies up to 400 keV ...
openaire   +2 more sources

Improved gamma radiation shielding traits of epoxy composites: Evaluation of mass attenuation coefficient, effective atomic and electron number

, 2021
To protect the human from the γ–radiation hazard, the novel shielding materials are ever-demanding in the field of nuclear medicine. In this research, we assessed the mass attenuation coefficient (μ/ρ), mean atomic number ( ), effective atomic cross ...
Mohammed J. R. Aldhuhaibat, M. S. Amana, Najwa J. Jubier, A. A. Salim   +3 more
semanticscholar   +1 more source

Photoionisation cross section of atomic oxygen

Journal of Physics B: Atomic and Molecular Physics, 1978
The photoionisation cross section for the ground state 2s22p4 3P of O I is calculated in the close-coupling approximation employing the frozen-cores model. Results include detailed resonance analysis using accurate interpolation and extrapolation procedures.
openaire   +1 more source

Ion-Rydberg atom collision cross sections

Journal of Physics B: Atomic and Molecular Physics, 1980
Classical-trajectory Monte Carlo calculations have been performed for collisions of ions in charge states q=+1, +2, +5 and +10 with hydrogenic atoms in principal quantum levels n=1, 2, 5, 10 and 20. The collision velocity range investigated was 1 or=2.
openaire   +1 more source

Electron-impact cross sections for Cu atoms

Journal of Physics B: Atomic and Molecular Physics, 1977
Relative differential electron-impact cross sections have been measured for elastic scattering for excitation of the 3d104p 2 P1/2,3/2, 3d94s2 2D5/2 and 3d94s2 2D3/2 states of Cu at 6, 10, 20, 60 and 100 eV in the 0 degrees to 140 degrees angular range.
S Trajmar, W Williams, S K Srivastava
openaire   +1 more source

Measurement of Differential Atomic Collision Cross Sections

Review of Scientific Instruments, 1971
An apparatus for the study of differential angular scattering of atomic projectiles by gas targets is described. The design facilitates system alignment and provides for accurate reproducible location of components. The performance of the instrument is studied for scattering of H+ at 5–25 keV energies by helium and argon targets.
R. L. Fitzwilson, E. W. Thomas
openaire   +1 more source