Open Access. Powered by Scholars. Published by Universities.®

Physics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

1988

Articles 1 - 8 of 8

Full-Text Articles in Physics

A Mössbauer Effect Study Of Y₂Fe₁₄B And Its Aluminum Solid Solutions, Dwayne E. Tharp, Gary J. Long, Oran Allan Pringle, Gaya Kanishka Marasinghe, William Joseph James, Fernande Grandjean Nov 1988

A Mössbauer Effect Study Of Y₂Fe₁₄B And Its Aluminum Solid Solutions, Dwayne E. Tharp, Gary J. Long, Oran Allan Pringle, Gaya Kanishka Marasinghe, William Joseph James, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The Mössbauer spectra of Y2Fe14B have been measured from 85 to 296 K. Analysis of the spectra indicates that the near-neighbor rare-earth atoms directly influence the orientation of the principal axis of the electric field gradient. The hyperfine parameters are very similar to those of Nd2Fe14B, but the internal fields are somewhat smaller at room temperature in the yttrium compound. The Mösssbauer spectra of Y2(Fe1-xAlx) 14B, where x equals 0.00, 0.02, 0.04, 0.06, and 0.08, have been measured at 85 K. The average internal hyperfine …

Go to article

A Neutron Diffraction And Mössbauer Spectral Study Of The Structure And Magnetic Properties Of The Y₂Fe₁₄₋ₓsiₓb Solid Solutions, Gaya Kanishka Marasinghe, Oran Allan Pringle, Gary J. Long, William B. Yelon, Fernande Grandjean Nov 1988

A Neutron Diffraction And Mössbauer Spectral Study Of The Structure And Magnetic Properties Of The Y₂Fe₁₄₋ₓsiₓb Solid Solutions, Gaya Kanishka Marasinghe, Oran Allan Pringle, Gary J. Long, William B. Yelon, Fernande Grandjean

Physics Faculty Research & Creative Works

A neutron diffraction and Mössbauer spectral study of Y2Fe14-xSixB shows that silicon preferentially occupies the 4c, and to a lesser extent, the 8j1 sites in Y2Fe14-xSixB. The trend in the site occupancy is the same as in Nd2Fe14-xSixB. The Curie temperature of Y2Fe14-xSixB increases with increasing silicon content. Neutron diffraction data show that the increase in Curie temperature is accompanied by a contraction of the unit cell. Wigner-Seitz cell calculations, using the Y2Fe …

Go to article

Slip, Twinning, And Fracture At A Grain Boundary In The L12 Ordered Structure—Aς = 9 Tilt Boundary, Alexander H. King, M. H. Yoo Oct 1988

Slip, Twinning, And Fracture At A Grain Boundary In The L12 Ordered Structure—Aς = 9 Tilt Boundary, Alexander H. King, M. H. Yoo

Alexander H. King

The role of interaction between slip dislocations and a Σ = 9 tilt boundary in localized microplastic deformation, cleavage, or intergranular fracture in the Li2 ordered structure has been analyzed by using the anisotropic elasticity theory of dislocations and fracture. Screw superpartials cross slip easily at the boundary onto the (1$\overline 1$1) and the (001) planes at low and high temperatures, respectively. Transmission of primary slip dislocations onto the conjugate slip system occurs with a certain degree of difficulty, which is eased by localized disordering. When the transmission is impeded, cleavage fracture on the ($\overline 1$11) plane is predicted to …

Go to article

30th Rocky Mountain Conference Jul 1988

30th Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 30th annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 31 - August 5, 1988.

Go to article

Erratum: Determination Of Dissociation Energies And Thermal Functions Of Hydrogen Bond Formation Using High Resolution Ftir Spectroscopy [J. Chem. Phys. 8 7, 5674 (1987)], B. A. Wofford, M. E. Eliades, Shannon Lieb, J. W. Bevan Jan 1988

Erratum: Determination Of Dissociation Energies And Thermal Functions Of Hydrogen Bond Formation Using High Resolution Ftir Spectroscopy [J. Chem. Phys. 8 7, 5674 (1987)], B. A. Wofford, M. E. Eliades, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

Erratum

Go to article

The Spectroscopy And Molecular Dynamics Of The High Frequency Ν1 6 Intermolecular Vibrations In Hcn‐‐‐Hf And Dcn‐‐‐Df, B. A. Wofford, M. W. Jackson, Shannon Lieb, J. W. Bevan Jan 1988

The Spectroscopy And Molecular Dynamics Of The High Frequency Ν1 6 Intermolecular Vibrations In Hcn‐‐‐Hf And Dcn‐‐‐Df, B. A. Wofford, M. W. Jackson, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

Gas phase rovibrational analysis of the high frequency intermolecular hydrogen bonded bending overtone 2ν0 6 [ν0=1132.4783(2) cm− 1] in HCN‐‐‐HF and its corresponding perdeuterated fundamental ν1 6 [ν0=409.1660(2) cm− 1] are reported. Evaluated rovibrational parameters provide the basis for quantitative modeling of the molecular dynamics associated with this vibration. A quantum mechanical calculation permits determination of the quadratic and quartic force constants K 6 6=537(17) and K 6 6 6 6=4.98(12) cm− 1 which in turn are used to estimate the pertinent cubic band stretching interaction constants …

Go to article

The Treatment Of Exchange In Path Integral Simulations Via An Approximate Pseudopotential, Randall W. Hall Jan 1988

The Treatment Of Exchange In Path Integral Simulations Via An Approximate Pseudopotential, Randall W. Hall

Collected Faculty and Staff Scholarship

An approximate form that includes the effects of exchange is suggested for the short time propagator used in path integral simulations. The form is inspired physically by the approximation made in Hartree–Fock treatments of atoms and molecules. The approximate propagator is used with q u a n t i t a t i v e accuracy in two systems: an ideal gas of fermions localized in a three‐dimensional harmonic well and the triplet state of the sodium dimer.

Go to article

Projectile-Charge Dependence Of Ejected-Electron Spectra, V. D. Irby, Timothy James Gay, Jimmie Garwin Edwards, Edward Boyd Hale, M. L. Mckenzie, Ronald E. Olson Jan 1988

Projectile-Charge Dependence Of Ejected-Electron Spectra, V. D. Irby, Timothy James Gay, Jimmie Garwin Edwards, Edward Boyd Hale, M. L. Mckenzie, Ronald E. Olson

Physics Faculty Research & Creative Works

We have studied H++He and He++3+He ionizing collisions at intermediate energies (60 to 120 keV/amu) and have observed a significant shift in the velocity position of the maxima in forward-ejected electron spectra when changing projectiles from protons to particles. In ionizing collisions, a large portion of the ejected electrons are stranded near the transitory equiforce, or saddle point, position between the target ion and receding projectile. The shift in the electron spectra maxima to smaller velocities, due to changing projectiles from protons to particles, is consistent with the shift in the saddle-point velocity when the projectile …

Go to article