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Full-Text Articles in Physical Sciences and Mathematics
Diffusion Of Nickel In Silicon Below 475 °C, G. L.P. Berning, L. L. Levenson
Diffusion Of Nickel In Silicon Below 475 °C, G. L.P. Berning, L. L. Levenson
Physics Faculty Research & Creative Works
Nickel films were deposited on (100) and (111) surfaces of single-crystal silicon and were then annealed. The conditions under which the nickel is deposited determine whether or not an NiSi compound forms on annealing. It is postulated that defects are necessary for the formation of an NiSi compound at annealing temperatures below at least 475 °C, although the presence of defects may not necessarily cause the formation of a silicide. For substrate temperatures below 70 °C, defects are created during the vapor deposition of nickel on silicon. These defects always result in the formation of nickel silicide when the sample …
Crystalline To Amorphous Transformation In Ion-Implanted Silicon: A Composite Model, John R. Dennis, Edward Boyd Hale
Crystalline To Amorphous Transformation In Ion-Implanted Silicon: A Composite Model, John R. Dennis, Edward Boyd Hale
Physics Faculty Research & Creative Works
The transformation of silicon to the amorphous state by implanted ions was studied both experimentally and theoretically. Experimentally, the amount of transformed silicon and the critical ion dose necessary to amorphized the entire implanted layer were determined by ESR. How the critical dose varies with ion mass (Li, N, Ne, Ar, and Kr), ion energy (20-180 keV), and implant temperature (77-475 K) was determined. Theoretically, several phenomenological models were used to analyze these data. The overlap-damage model was used to determine the critical dose from the data, the size of the amorphous region around the ion track, and the degree …
Electron Attachment In Dilute Fluorine-Helium Mixtures, Kaare J. Nygaard, Scott R. Hunter, John L. Fletcher, Stephen R. Foltyn
Electron Attachment In Dilute Fluorine-Helium Mixtures, Kaare J. Nygaard, Scott R. Hunter, John L. Fletcher, Stephen R. Foltyn
Physics Faculty Research & Creative Works
We have made an absolute determination of the electron attachment coefficient η (cm-1) in helium containing 0.1-1% fluorine covering an E/N range from 3Td-17Td. At an estimated average energy of 5 eV we find a rate coefficient equal to (7.5±1.5) x10-10 cm3/sec.
High-Flux Beam Source Of Fast Neutral Helium, D. W. Fahey, Laird D. Schearer, William F. Parks
High-Flux Beam Source Of Fast Neutral Helium, D. W. Fahey, Laird D. Schearer, William F. Parks
Physics Faculty Research & Creative Works
A high-flux beam source of fast neutral helium has been constructed by extending the designs of previous authors. The source is a dc or pulsed electric discharge in an expanding gas nozzle. The beam produced has a flux on the order of 1015 atoms/ssr and a mean velocity on the order of 107 cm/s. The composition of the beam has been determined by the use of particle detectors and by the observation of the excitation of certain target gases. An upper bound of 3.7*10-5 has been estimated for the He(2 3S1)/He(1S0) beam density ratio and a value of 0.2 found …
The Formation And Decomposition Of Nickel Carbide In Evaporated Nickel Films On Graphite, S. Sinharoy, L. L. Levenson
The Formation And Decomposition Of Nickel Carbide In Evaporated Nickel Films On Graphite, S. Sinharoy, L. L. Levenson
Physics Faculty Research & Creative Works
Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to study nickel carbide (Ni3C) formed during the evaporation of nickel onto the surface of single-crystal graphite. It is shown that Ni3C formed in this manner extends from the surface to close to the interface. A model is proposed to explain the mechanism of Ni3C formation. The 1s photoelectron peak from Ni3C is observed to have a binding energy 0.6 eV lower than that of pure graphite. This is attributed to the lack of any significant ionic bonding in Ni3C. © 1978.
Angular Differential Cross Sections For 25-, 50-, And 100-Kev-Proton Excitation Of Helium To The N=2 Level, John T. Park, Jacob M. George, Jerry Peacher, Judith E. Aldag
Angular Differential Cross Sections For 25-, 50-, And 100-Kev-Proton Excitation Of Helium To The N=2 Level, John T. Park, Jacob M. George, Jerry Peacher, Judith E. Aldag
Physics Faculty Research & Creative Works
Differential cross sections for 25-, 50-, and 100-keV-proton excitation of helium to the n=2 level have been determined for center-of-mass scattering angles from 0 to 1.2 mrad. The cross sections were obtained from an analysis of the angular distribution of the scattered protons which had lost an energy corresponding to the excitation of the helium target to its n=2 level. The differential cross section is very sharply peaked in the forward direction and decreases by a factor of 45 in 1.0 mrad at 25 keV and by a factor of 650 in 1.0 mrad at 100 keV. The data are …
Angular Differential Cross Sections For Excitation Of Atomic Hydrogen By 25-, 50-, And 100-Kev Protons, John T. Park, Judith E. Aldag, Jerry Peacher, Jacob M. George
Angular Differential Cross Sections For Excitation Of Atomic Hydrogen By 25-, 50-, And 100-Kev Protons, John T. Park, Judith E. Aldag, Jerry Peacher, Jacob M. George
Physics Faculty Research & Creative Works
Angular differential cross sections for the process H+ + H(1s ) → H+ (θ ) + H ( n = 2 ) are presented for 25-, 50-, and 100-keV protons incident on atomic hydrogen. The experimental results are in fair agreement with Glauber-approximation calculations.
Electron Drift Velocities In Helium-Fluorine Gas Mixtures, Kaare J. Nygaard, John L. Fletcher, Scott R. Hunter, Stephen R. Foltyn
Electron Drift Velocities In Helium-Fluorine Gas Mixtures, Kaare J. Nygaard, John L. Fletcher, Scott R. Hunter, Stephen R. Foltyn
Physics Faculty Research & Creative Works
Using a simple time-of-flight technique, we have measured the electron drift velocity in helium with 0.1-1% fluorine additive. Our results in a 0.1% mixture are in close agreement with data in pure helium. The measured drift velocity increases with increasing fluorine concentration. © 1978, American Institute of Physics. All rights reserved.
Production Of Cl⁻·Hcl Cluster Ions In Hcl-N2 Mixtures, R. J. Corbin, Kaare J. Nygaard, William R. Snow, Laird D. Schearer
Production Of Cl⁻·Hcl Cluster Ions In Hcl-N2 Mixtures, R. J. Corbin, Kaare J. Nygaard, William R. Snow, Laird D. Schearer
Physics Faculty Research & Creative Works
A drift-tube-mass-spectrometer apparatus has been used to study the production of Cl-·HCl cluster molecules in HCl-N2 mixtures. The concentration of HCl was 730 ppm and the total pressure ranged from 0.1-5 Torr. The primary ion Cl- is produced mainly by dissociative attachment of HCl and is converted to a cluster ion in a three-body collision. The rate of formation of the cluster ion is k2≃ 10-25 cm6/sec at E/N=12 Td. © 1978 American Institute of Physics.
The Bethe‐Peierls‐Weiss Approximation For Amorphous Magnets, Harry A. Brown
The Bethe‐Peierls‐Weiss Approximation For Amorphous Magnets, Harry A. Brown
Physics Faculty Research & Creative Works
No abstract provided.
Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones
Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones
Physics Faculty Research & Creative Works
The cross section for photoionization of potassium atoms in the 4P2 states has been measured in a triple-crossed-beam experiment. © 1978 The American Physical Society.
A Xenon Ion Pumped Blue Dye Laser, D. W. Fahey, Laird D. Schearer
A Xenon Ion Pumped Blue Dye Laser, D. W. Fahey, Laird D. Schearer
Physics Faculty Research & Creative Works
A pulsed xenon ion laser with an output power of 5 kW at 364.5 nm has been used as a pump source for several blue dyes. Broadband conversion efficiencies exceed 20 percent. The use of a birefringent filter provides tunable output in the blue region of the spectrum with a bandwidth of 0.08 nm and a pulse width of 120 ns. © 1978 IEEE
Note On The Constant Coupling Approximation, M. Jursich, Harry A. Brown
Note On The Constant Coupling Approximation, M. Jursich, Harry A. Brown
Physics Faculty Research & Creative Works
No abstract provided.
On The Classical‐Spin Model Of Amorphous Ferromagnets, Harry A. Brown
On The Classical‐Spin Model Of Amorphous Ferromagnets, Harry A. Brown
Physics Faculty Research & Creative Works
No abstract provided.
Time Resolved Fluorescence Of The A ²∑+ State Of Gef, R. (Richard) A. Anderson, L. Hanko, S. J. Davis
Time Resolved Fluorescence Of The A ²∑+ State Of Gef, R. (Richard) A. Anderson, L. Hanko, S. J. Davis
Physics Faculty Research & Creative Works
The radiative lifetime and quenching rates for the A 2∑ + state of GeF have been measured in the flame of GeH 4+F2 by pulsed laser induced fluorescence. In addition, the radiative lifetime of the ν′=0 level of the A 2∑ + state of SiF has been measured in the flame of SiH 4+F2. Quenching rates for He, N2, and SF 6 on GeF A 2∑ and He on SiF A 2∑ have also been determined. The average zero pressure lifetime of ν′=0, 1, and 2 levels of A 2∑ GeF is 990±100 nsec. The zero-pressure lifetime of the A …
Spin Correlations In Actinide Materials: A Neutron Study Of Usb, G. H. Lander, S. K. Sinha, Don M. Sparlin, O. Vogt
Spin Correlations In Actinide Materials: A Neutron Study Of Usb, G. H. Lander, S. K. Sinha, Don M. Sparlin, O. Vogt
Physics Faculty Research & Creative Works
Measurements have been made of the short-range spin correlations in USb, a metallic compound that orders antiferromagnetically. The system has no transverse fluctuations, and the longitudinal spin correlations are anisotropic, showing stronger interactions within the ferromagnetic sheets than between them. The results of this and other experiments can be understood with simple concepts involving the bonding of 5f electrons. © 1978 The American Physical Society.