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Full-Text Articles in Physics
Nickel Carbide: Its Formation And Characterization By Transmission Electron Diffraction, Auger Electron Spectroscopy And Electron Spectroscopy For Chemical Analysis, J. Kleefeld, L. L. Levenson
Nickel Carbide: Its Formation And Characterization By Transmission Electron Diffraction, Auger Electron Spectroscopy And Electron Spectroscopy For Chemical Analysis, J. Kleefeld, L. L. Levenson
Physics Faculty Research & Creative Works
Nickel carbide (NiC3) films are formed by the carburization of nickel films in CO at 350°C. The presence of Ni3C is demonstrated by transmission electron diffraction. The carbon Auger electron signal of Ni3C is identical with the carbon Auger spectra attributed to Ni3C by previous authors. The position of the C 1s electron spectroscopy for chemical analysis peak is within 1 eV of the C 1s peak produced by graphite. The grain size of polycrystalline Ni3C is significantly larger than the grain size of the nickel film from which it is grown. © 1979.
The Hanle Effect In Penning-Excited Ions, D. W. Fahey, William F. Parks, Laird D. Schearer
The Hanle Effect In Penning-Excited Ions, D. W. Fahey, William F. Parks, Laird D. Schearer
Physics Faculty Research & Creative Works
A thermal beam of helium (23S1) metastable atoms was used to excite coherently the 2P3/2 levels of Ca, Sr and Ba in a Penning ionizing collision. The coherent excitation of the ions appears as a linear polarization of the optical emission from the excited ions. The degree of linear polarization is 5.5, 3.5 and 0.5% for Ca, Sr and Ba, respectively, with the polarization parallel to the beam direction. Hanle effect signals from the 2P3/2 level of Sr were observed and the radioactive decay rate measured.
Conductive Strontium Titanate Layers Produced By Boron-Ion Implantation, Connie M. Cooper, P. S. Nayar, Edward Boyd Hale, Robert Gerson
Conductive Strontium Titanate Layers Produced By Boron-Ion Implantation, Connie M. Cooper, P. S. Nayar, Edward Boyd Hale, Robert Gerson
Physics Faculty Research & Creative Works
The ion implantation of boron has been found to be an effective method for increasing the conductivity of strontium titanate. A highly conductive layer was formed by implantations at doses of 3.6x1016 to 1.0x1017 ions/cm2, using an accelerating voltage of 100 kV, corresponding to a boron range of about 300 nm. The conductivity of the implanted layer was found to be further enhanced by about four orders of magnitude after annealing at 225 °C. The surface resistivity attained was typically 1000 Ω/square at room temperature. The resistance increased with rising temperature between 77 and 500 K. All samples were found …
Electron Drift Velocities In N2, Co2, And (N 2+Co2) Laser Mixtures, Rafael A. Sierra, Howard L. Brooks, Kaare J. Nygaard
Electron Drift Velocities In N2, Co2, And (N 2+Co2) Laser Mixtures, Rafael A. Sierra, Howard L. Brooks, Kaare J. Nygaard
Physics Faculty Research & Creative Works
A time-of-flight technique has been used to obtain electron drift velocities in N2, CO2, and N2-CO2 mixtures covering the E/N range 3-93 Td. In the case of the pure gases, excellent agreement with previous work is obtained over the entire E/N range. The mixtures, which are of laser importance, have not been studied previously.
Doubly Differential Cross Sections For Proton-Impact Ionization Of Argon, Don H. Madison, Steven Trent Manson
Doubly Differential Cross Sections For Proton-Impact Ionization Of Argon, Don H. Madison, Steven Trent Manson
Physics Faculty Research & Creative Works
Proton-impact-ionization cross sections for argon which are differential in the energy and angle of the ejected electron have been calculated within the framework of the Born approximation using both Hartree-Slater and Hartree-Fock wave functions for the ejected electron. Results of the two types of calculations are compared with each other and with experiment. Differential cross sections for all five sub shells of argon are examined and particular attention is given to some interesting features of the K-shell cross sections. The range of applicability of the theoretical models is discussed.
Negative Ion Production Rates In Rare Gas-Halide Lasers, Kaare J. Nygaard, Howard L. Brooks, Scott R. Hunter
Negative Ion Production Rates In Rare Gas-Halide Lasers, Kaare J. Nygaard, Howard L. Brooks, Scott R. Hunter
Physics Faculty Research & Creative Works
This paper reports on dissociative electron attachment in F2, NF3, Cl2, and I2. The principle of the method is to produce a short burst of photoelectrons from a photocathode by means of light from an argon-fluoride laser. Subsequently, by studying the motion of electrons and negative ions in a constant electric field (E) region, information is obtained about drift velocities and effective attachment cross sections. Helium, argon, and nitrogen were used as buffer gases. Of particular interest is a very strong temperature dependence of the attachment coefficient in I2. Measurements were taken from 35 to 110°C, covering an E/N range …
Excitation Of Cd, Zn, And Sr By A Beam Of Active Nitrogen, D. W. Fahey, William F. Parks, Laird D. Schearer
Excitation Of Cd, Zn, And Sr By A Beam Of Active Nitrogen, D. W. Fahey, William F. Parks, Laird D. Schearer
Physics Faculty Research & Creative Works
Excitation of the electronic levels of Cd, Zn, and Sr is observed when these metal vapors collide with a thermal-energy, active nitrogen beam. The beam is extracted from a glow discharge in pure N2. The active beam component is inferred to be vibrationally excited N2 in the A 3Σu+ electronic state. The absolute relative intensity of the emission lines in each element was measured. The excitation rates of the Cd and Zn target levels were found to depend exponentially on their energies indicating an effective temperature of approximately 4000°K. We believe that this temperature is related to the vibrational temperature …
Temperature Dependence Of The Electron Attachment Coefficient In Iodine, Howard L. Brooks, Scott R. Hunter, Kaare J. Nygaard
Temperature Dependence Of The Electron Attachment Coefficient In Iodine, Howard L. Brooks, Scott R. Hunter, Kaare J. Nygaard
Physics Faculty Research & Creative Works
The attachment coefficient for iodine in a (1% I2+99% N 2) mixture, 50 Torr total pressure, has been measured in an electron swarm experiment from 1 to 50 Townsends (1 Townsend=1Td=10-17 V cm2). As the temperature was increased from 35 to 110°C, the attachment coefficient increased for any E/N (electric field intensity/gas number density) values greater than 7 Td. These results are compared to other experimental data and an explanation for the temperature dependence, based on the population of upper vibrational states, is presented. © 1979 American Institute of Physics.
The Oguchi-Kaneyoshi Method For Spin-Glasses, M. Jursich, Harry A. Brown
The Oguchi-Kaneyoshi Method For Spin-Glasses, M. Jursich, Harry A. Brown
Physics Faculty Research & Creative Works
The results of an effective field calculation of the phase diagram and order parameters for a random exchange Ising model are presented. This calculation was based on an exchange coupled pair instead of the single-spin molecular-field theory. This approach should be an improvement over the infinite-ranged models because it includes localized effects. The results indicate that the local disorder effects are especially important at low temperatures. © 1979, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.
Dissociative Excitation Of Hgbr2 In Collisions With A Beam Of Metastable Nitrogen, D. W. Fahey, Laird D. Schearer
Dissociative Excitation Of Hgbr2 In Collisions With A Beam Of Metastable Nitrogen, D. W. Fahey, Laird D. Schearer
Physics Faculty Research & Creative Works
No abstract provided.
Alignment Of Ions In Penning Collisions, D. W. Fahey, Laird D. Schearer, William F. Parks
Alignment Of Ions In Penning Collisions, D. W. Fahey, Laird D. Schearer, William F. Parks
Physics Faculty Research & Creative Works
The authors have observed the alignment of the 5p P322 state of strontium ions produced in Penning collisions between an unpolarized beam of helium metastable atoms and a strontium vapor target. The alignment is shown by a linear polarization of the optical emission from the excited ion. For a 66-meV beam of helium metastable atoms a 3.5% linear polarization of the emission relative to the beam axis was measured. It is shown how the alignment may be used to determine the probabilities for populating the various final Quasi molecular states of the ion-atom pair. The alignment of the Penning ions …
Precision Doubly Differential Cross Section Measurements, John T. Park
Precision Doubly Differential Cross Section Measurements, John T. Park
Physics Faculty Research & Creative Works
Ion Energy Loss Spectrometry has been applied to the measurement of cross sections differential in both scattering angle and ion energy loss. Differential cross sections obtained for excitation of the n=2 level of atomic hydrogen by various ions provides unexpectedly good agreement with the available theories. Copyright © 1978 by The Institute of Electrical and Electronics Engineers, Inc.