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A Study Of Bismuth Ferrate And Bismuth Manganate In Solid Solution With Lead Titanate, Harris C. Jones Jan 1968

A Study Of Bismuth Ferrate And Bismuth Manganate In Solid Solution With Lead Titanate, Harris C. Jones

Masters Theses

"A new sample holder for measuring the high frequency dielectric constant of ferroelectrics at high temperature was constructed. The new sample holder eliminated discontinuities in the slotted line and improved the electrical contact between the ceramic and brass components. Measurements of the high frequency dielectric constant of an aged sample of 90% BiFeO₃ - 10% PbTiO₃ were made as a function of temperature using the slotted line technique. The dissipation function for the aged sample was found to have a more normal behavior near the Curie point than the virgin samples previously measured. Resistivity measurements were made as a function …

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Mechanical Effects Of Acoustic Transients On Tobacco Mosaic Virus, Philip Edward Hamrick Jan 1968

Mechanical Effects Of Acoustic Transients On Tobacco Mosaic Virus, Philip Edward Hamrick

Theses and Dissertations

The mechanical breakage of tobacco mosaic virus (TMV) due to the action of acoustic transients has been investigated. The acoustic transients were produced by transient heating of a Prussian blue dye solution (attenuation coefficient of 1000 per cm) when a ruby laser light (20 x 106 watts) was incident on the dye surface. A quartz piezoelectric transducer was used to determine the amplitude and form of the acoustic wave. The production of acoustic waves by transient heating is discussed, and the theoretical form of the acoustic wave determined for various boundary and initial conditions are compared to the experimentally …

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Dielectric Properties Of Solid Solutions Of Bifeo₃ With Pb(Ti, Zr)O₃ At High Temperature And High Frequency, Robert Travis Smith, Gary D. Achenbach, Robert Gerson, William Joseph James Jan 1968

Dielectric Properties Of Solid Solutions Of Bifeo₃ With Pb(Ti, Zr)O₃ At High Temperature And High Frequency, Robert Travis Smith, Gary D. Achenbach, Robert Gerson, William Joseph James

Physics Faculty Research & Creative Works

Solid solutions of BiFeO3 with PbTiO3, PbTi0.5Zr0.5O3, and PbZrO3 were prepared. The crystallographic data on these solutions, which are basically perovskitic, are given. The dielectric constants of the materials were determined at a frequency of 0.53 GHz and at temperatures up to 800°C. Dielectric Curie points were found in solutions containing up to 90 mole % BiFeO3. These results leave little doubt that BiFeO3 is ferroelectric or antiferroelectric. The extrapolated Curie point for BiFeO3 is above 850°C. BiFeO3 appears more likely to be ferroelectric than …

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The Critical And High‐Temperature Behavior Of A Heisenberg Ferromagnet, Harry A. Brown Jan 1968

The Critical And High‐Temperature Behavior Of A Heisenberg Ferromagnet, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

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The Magnetic Dilution Problem, Harry A. Brown, William F. Parks Jan 1968

The Magnetic Dilution Problem, Harry A. Brown, William F. Parks

Physics Faculty Research & Creative Works

No abstract provided.

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Cell Model Of A Fluid. I. Evaluation Of The Partition Function And Series Expansions, Ralph G. Tross, Louis H. Lund Jan 1968

Cell Model Of A Fluid. I. Evaluation Of The Partition Function And Series Expansions, Ralph G. Tross, Louis H. Lund

Physics Faculty Research & Creative Works

The partition function of a one-dimensional system of particles with all interactions active is formulated in terms of Ising ferromagnetic spin states. It is shown how the partition function for two- and three-dimensional systems can be obtained from the one-dimensional one by restricting the number of bonds per particle. After writing the partition function in matrix form, the operator of interest is diagonalized and its trace expressed in the form of a convenient infinite series. The series is shown to be absolutely convergent and its analytic properties are briefly investigated. It is then applied to one-, two-, and three-dimensional systems …

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Cell Model Of A Fluid. Ii. Thermodynamic Properties Of The System, Ralph G. Tross, Louis H. Lund Jan 1968

Cell Model Of A Fluid. Ii. Thermodynamic Properties Of The System, Ralph G. Tross, Louis H. Lund

Physics Faculty Research & Creative Works

In Paper I of this series (preceding paper) the model was formulated mathematically, and the solution derived in the form of an infinite series. The convergence and analyticity of the solution were investigated. It was then applied to one-, two-, and three-dimensional systems with nearest-neighbor interactions, and low-temperature series for these systems were obtained. In the present article the thermodynamics of the model are investigated. The series solution of the partition function derived in Paper I is applied to systems with interaction potentials of increasing complexity. The validity of the model is established by showing that in the appropriate limits …

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The Bethe-Weizsäcker Mass Formula And Lennard-Jones N-N Potentials, James Paul Wesley, Alex E.S. Green Jan 1968

The Bethe-Weizsäcker Mass Formula And Lennard-Jones N-N Potentials, James Paul Wesley, Alex E.S. Green

Physics Faculty Research & Creative Works

An elementary derivation of the Bethe-Weizscker semiempirical nuclear mass formula which is in the spirit of current views of nuclear structure, is given. Lennard-Jones potentials are assumed to act between nuclear. Thus, the major interaction between nn, pp, and np pairs is taken of the form —g/r3+h/r4, where r is the separation distance between nuclear, and g and h are constants. An additional "symmetry" interaction of the form s/r3 is assumed for np pairs. Summing the potential energy over all nucleon pairs and using the Fermi statistical estimate of the kinetic energy, the Bethe-Weizscker semiempirical mass formula is obtained directly. …

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Optimum Spacing Of Square And Circular Coil Pairs, M. Eugene Rudd, J. R. Craig Jan 1968

Optimum Spacing Of Square And Circular Coil Pairs, M. Eugene Rudd, J. R. Craig

M. Eugene Rudd Publications

In a previous note Crownfield pointed out that the magnetic field along the axis of a coil pair is within a prescribed uniformity over a substantially longer region than that given by the Helmholtz spacing if a somewhat larger spacing is used. In the note, values of coil spacing and length of uniform field region are given for a few desired uniformities, but only for a particular "thick" coil pair, i.e., one with cross-sectional dimensions comparable to the spacing. Many coil pairs, such as those used to annul the earth's field over the region occupied by some apparatus, have cross-sectional …

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Excitation Of Auto-Ionizing Levels In Neon By Ion Impact, A. K. Edwards, M. Eugene Rudd Jan 1968

Excitation Of Auto-Ionizing Levels In Neon By Ion Impact, A. K. Edwards, M. Eugene Rudd

M. Eugene Rudd Publications

Auto-ionizing states of neutral and singly ionized neon were produced by bombarding neon gas with H+, He+, and Ne+ ions in the 150-250-keV energy range. Sixty lines in the electron spectrum were found, of which 43 have been classified into 13 Rydberg series. Ten of these series were previously unreported. Auger electrons from one- and two-vacancy states are also reported. Relative intensities of all transitions are listed.

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Energy Spectra Of Auto-Ionizing Electrons In Oxygen, M. Eugene Rudd, Kenneth Smith Jan 1968

Energy Spectra Of Auto-Ionizing Electrons In Oxygen, M. Eugene Rudd, Kenneth Smith

M. Eugene Rudd Publications

Experimental and theoretical data are presented showing the energy spectra of auto-ionizing electrons from atomic oxygen. The experimental data were obtained by bombarding oxygen gas with 100-keV H+ and He+ ions; the theoretical results were obtained in a close-coupling calculation which coupled the 4S, 2D, and 2P terms of the ground-state configuration of O+ in electron-O+ scattering.

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An Experimental Determination Of The Homogeneous Nucleation Rate Of Water Vapor In Argon And Helium, Louis Benton Allen Jan 1968

An Experimental Determination Of The Homogeneous Nucleation Rate Of Water Vapor In Argon And Helium, Louis Benton Allen

Doctoral Dissertations

"An expansion type cloud chamber was used to measure the nucleation rate of water vapor in an atmosphere of helium and argon. A careful study was made of the thermodynamic characteristics during the expansion so that the nucleation data could be interpreted with reasonable accuracy and consistency. A fine wire thermocouple was used to measure the gas temperature during the course of an isentropic expansion in the dry chamber. When the finite heat capacity of the thermocouple is accounted for, it is found that there is almost perfect agreement with the temperature calculated from the equation of state and the …

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The Lifetime And Effective Quenching Cross Section Of The 6²P₃/₂ State Of Thallium, Robert Charles Pickett Jan 1968

The Lifetime And Effective Quenching Cross Section Of The 6²P₃/₂ State Of Thallium, Robert Charles Pickett

Doctoral Dissertations

"The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power …

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Electronic Transitions In Diatomic Molecules, James O. Hornkohl Jan 1968

Electronic Transitions In Diatomic Molecules, James O. Hornkohl

Masters Theses

"The electronic transition moments of many band systems have been found to be linear functions of the internuclear distance. However, some band systems exhibit a quadratic variation of the transition moment. In these quadratic cases, the plots from which the variation of the transition moment is determined are based upon the approximation of the second r-centroid by the square of the first r-centroid. The square of the first r-centroid does closely approximate the second r-centroid by a simple error analysis shows that the small difference between the two is not a quantitative measure of the error introduced into the transition …

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Infrared Related Solid State Studies, Donald George Rathbun Jan 1968

Infrared Related Solid State Studies, Donald George Rathbun

Masters Theses

"Infrared reflectivity measurements have been made on single crystal CdS. Classical dispersion analysis has been used in an analysis of the data to obtain the index of refraction, the extinction index, and the dispersion parameters. These are compared with previously published results. The procedure used in this analysis has been outlined for future reference. Also, the shallow donor impurity theory has been used to numerically calculate the d±1 levels for Si and Ge. The theory is extended for the case of the impurity in the bulk semiconductor and the d₀, d±2 and, for high n, the s, p₀, …

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A Study Of Bifeo₃ And The Hall Effect In Bifeo₃ And Cds, Fred Hoerger Taylor Jan 1968

A Study Of Bifeo₃ And The Hall Effect In Bifeo₃ And Cds, Fred Hoerger Taylor

Masters Theses

"Pure samples of BiFeO₃ were heat treated in oxygen and nitrogen atmospheres in an attempt to reduce the conductivity of the samples. Dielectric constant and dissipation factor measurements, as a function of frequency, were made to determine whether the samples had been altered. A special high temperature Hall effect apparatus was constructed. Using this apparatus an upper limit for the Hall mobility in BiFeO₃ was established. The apparatus was also used for room temperature measurements of Ga-doped CdS samples. Resistivity measurements to be used with the Hall effect results were made on both the BiFeO₃ and the CdS samples. Hot-Point …

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Properties And Structure Of Some Chalcogenide Glasses, Amin Ismail Amin Abdel-Latif Jan 1968

Properties And Structure Of Some Chalcogenide Glasses, Amin Ismail Amin Abdel-Latif

Archived Theses and Dissertations

No abstract provided.

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Catalytic Decomposition Of Hydrogen Peroxide By Manganese-Doped Magnesium Hydroxide, Nabih Philobbos Kelada Jan 1968

Catalytic Decomposition Of Hydrogen Peroxide By Manganese-Doped Magnesium Hydroxide, Nabih Philobbos Kelada

Archived Theses and Dissertations

No abstract provided.

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Hyperfine-Structure Separations, Nuclear Magnetic Moments, And Hyperfine-Structure Anomalies Of Gold-198 And Gold-199, Paul A. Vanden Bout, Vernon J. Ehlers, William A. Nierenberg, Howard A. Shugart Dec 1967

Hyperfine-Structure Separations, Nuclear Magnetic Moments, And Hyperfine-Structure Anomalies Of Gold-198 And Gold-199, Paul A. Vanden Bout, Vernon J. Ehlers, William A. Nierenberg, Howard A. Shugart

University Faculty Publications and Creative Works

We have measured the hyperfine-structure separations and nuclear magnetic moments of (2.70-day) Au198 and (3.15-day) Au199 in the S122 state, using the atomic-beam magnetic-resonance method. We also measured the ratios of the electronic g factor of gold to those of potassium and cesium. The results are, for Au198 (I=2), Δν=21450.7167(4) MHz, μI(uncorr)=+0.5842(4) nm; and for Au199 (I=32), Δν=10962.7227(3) MHz, μI(uncorr)=+0.2673(7) nm. The results for the g-factor ratios are: gJ(Au)gJ(K)=1.000504(2) and gJ(Au)gJ(Cs)=1.000381(2). These values yield the following hyperfine-structure anomalies: Δ198197=8.53(8)% and Δ199197=3.7(2)%. Second-order corrections to the hyperfine structure are shown to be negligible. The nuclear results are interpreted in terms of …

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Strong-Coupled Piezoelectric Polaron, Wayne E. Tefft Dec 1967

Strong-Coupled Piezoelectric Polaron, Wayne E. Tefft

Physics Faculty Research & Creative Works

A semiclassical, variational calculation for the strong-coupled piezoelectric polaron gives the following results for the ground-state energy and polaron radius, respectively: U0=-0.47(m*/m) (κ2/ε)2eV, and R=3.5(ε/κ2) (m/m*)â ã where m* is the band effective mass, κ is the electromechanical coupling constant, and ε is the strain-free dielectric constant. The theory is expected to be valid when |U0| is larger than thermal energies and R is considerably larger than unit-cell dimensions. A calculation of the polaron effective mass, having a more limited region of validity, gives mp~m*[1+2|U0|/m*vs2], where vs is the velocity of sound. …

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Survival Probability In Dissociative Attachment, Joseph C.Y. Chen, Jerry Peacher Nov 1967

Survival Probability In Dissociative Attachment, Joseph C.Y. Chen, Jerry Peacher

Physics Faculty Research & Creative Works

The survival probability in dissociative attachment is investigated with special attention to the (e, H2 ) system. It is shown that the simple expression for the dissociative-attachment cross section, as given by the product of a capture cross section and a survival probability, is equivalent to the s -wave approximation for the g → g dissociative attachment. This expression, however, does not constitute an approximation for the g → u dissociative attachment, since the parity of the initial rotational states of H2 is always opposite to that of the relative angular momentum states of H and H- …

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Comparison Of Isobar Production In Pp And P̅N Interactions At 2.8 Gev/C, William J. Fickinger Oct 1967

Comparison Of Isobar Production In Pp And P̅N Interactions At 2.8 Gev/C, William J. Fickinger

Faculty Scholarship

The reactions pp→N*++(1238)n and p̅ n→N̅ *--(1238)p at 2.8 GeV/c incident laboratory momentum are analyzed with the Brookhaven National Laboratory 20-in. bubble chamber. Isobar and anti-isobar production differential cross sections and decay angular distributions are compared with the predictions of an absorptive single-pion-exchange model. The absolute values, shapes, and ratios of the cross sections are in good agreement with the theory when the absorptive parameters γ1 and γ2 are 0.033 and 0.016 for the p̅ n reaction, and 0.057 and 0.019, respectively, for the pp reaction.

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Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner Sep 1967

Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner

Faculty Publications

The variation in the electron paramagnetic resonance (EPR) spectrum of ruby as a function of pressure has been observed to beyond 70 kbar for a magnetic field orientation parallel to the crystalline c axis. The data can be interpreted in terms of the usual spin Hamiltonian, where the spectroscopic splitting factor g|| has the same value as at ambient pressures, but where the zero-field splitting deltaincreases in a linear fashion from 0.38 to 0.43 cm. The experimental apparatus has been described previously, although important improvements in the pressure seal and in the pressure calibration have been made and are described …

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Mössbauer Study Of Ferrimagnetic Ordering In Nickel Ferrite And Chromium-Substituted Nickel Ferrite, J. Chappert, Richard B. Frankel Sep 1967

Mössbauer Study Of Ferrimagnetic Ordering In Nickel Ferrite And Chromium-Substituted Nickel Ferrite, J. Chappert, Richard B. Frankel

Physics

Mössbauer-effect measurements in external magnetic fields show that the magnetic structure of ferrimagnetic NiFe2O4 is the collinear Néel type. NiFe0.3Cr1.7O4 is shown to have a triangular structure with θA=20±10° and θB=50±4°.

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High-Field Magnetoresistance Of Ordered Beta Brass , David J. Sellmyer, J. Ahn, J.-P. Jan Sep 1967

High-Field Magnetoresistance Of Ordered Beta Brass , David J. Sellmyer, J. Ahn, J.-P. Jan

David Sellmyer Publications

The magnetoresistance of several single-crystal specimens of ordered β-brass has been investigated in fields up to 150 kG. The purity of the samples is sufficiently high (ρ295/ρ4.2≃400) that the high-field condition is satisfied. The results indicate that ordered β-brass is an uncompensated metal and that its Fermi surface is multiply connected. Strong open orbits were observed when the field was in {110} or {100} planes, and this behavior is compatible with the Fermi-surface model predicted by augmented-plane-wave and Green's-function energy-band calculations. Evidence for the existence of higher-order open orbits and two-dimensional regions of open orbits is …

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The Kinetics Of Phase Transitions In Solid Cyclohexanol And Related Plastic Crystals., William Thomas Griffith Aug 1967

The Kinetics Of Phase Transitions In Solid Cyclohexanol And Related Plastic Crystals., William Thomas Griffith

Physics & Astronomy ETDs

The phase relations and the kinetics of phase transitions in the solid -forms of cyclohexanol, cyclohexanone, chlorocyclohexane, bromocyclohexane, and cyclopentanol have been investigated. Cyclohexanol has been studied the most thoroughly; the other compounds have been considered largely for purposes of comparison with cyclohexanol. The primary methods of investigation have been the measurement of dielectric properties and visual observations. The transitions in cyclohexanol have also been followed photographically in order to measure the growth velocities of the phase interfaces.

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Room-Temperature Second-Order Raman Spectra Of Csc1, Csbr, And Csi, A. M. Karo, John R. Hardy Aug 1967

Room-Temperature Second-Order Raman Spectra Of Csc1, Csbr, And Csi, A. M. Karo, John R. Hardy

John R. Hardy Papers

The room-temperature Raman spectra of CsC1, CsBr, and CsI have been computed from a simple, combined density-of-states approximation. Calculations have been made for four different model potential functions and compared with experiment in the cases of CsBr and CsI. In this way it is found that one of the variations, called the DD(-) model, is the most satisfactory. The agreement with the observed spectra is surprisingly close when one considers that no allowance has been made for variations in the elements of the Raman polarizability tensor.

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9th Annual Meeting Rocky Mountain Spectroscopy Conference Aug 1967

9th Annual Meeting Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 9th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 7-8, 1967.

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Measurement Of Ultrasonic Absorption In Liquids By A Thermal Method, Ronald J. Tanis Aug 1967

Measurement Of Ultrasonic Absorption In Liquids By A Thermal Method, Ronald J. Tanis

Masters Theses

No abstract provided.

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Noise In Cadmium Sulfide & Cadmium Selenide Photoconductive Cells, Edward Foster Aug 1967

Noise In Cadmium Sulfide & Cadmium Selenide Photoconductive Cells, Edward Foster

Masters Theses & Specialist Projects

The primary object of this investigation is to design a system, including equipment and procedures, that can be used to evaluate the noise characteristics of photoconductive cells. The data once collected must be in a comprehensive and useful form. The secondary object is to use this system to evaluate a large number of cells of various types and to compare their noise profiles in a manner such that definite conclusions can be drawn concerning the absolute noise levels and profiles generated by the various cell types and the relations that may exist between the cells' noise output and the way …

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