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Interpretation of Resonant Photoemission Spectra of Solid Actinide Systems

June 15, 2001

Author(s)

S Molodtsov, S Halilov, M Richter, A Zangwill, C Laubschat

It is shown that angle-resolved valence-band photoemission (PE) spectra of epitaxial close-packed films of U metal may correctly be described within a one-step model of PE based on a band description of the U 5f states. It is found that a cross-section

Frequency Dependence of a Cryogenic Capacitor Measured Using Single Electron Tunneling Devices

December 1, 2000

Author(s)

Ali L. Eichenberger, Mark W. Keller, John M. Martinis, Neil M. Zimmerman

A new type of capacitance standrd based on counting electrons has been built. The operation of the standrd has already given very promising results for the determination of the value of a cryogenic vacuum-gap capacitor. The new capacitance standard

Cooper Minima in the Photoemission Spectra of Solids

November 6, 2000

Author(s)

S Molodtsov, S Halilov, V Servedio, W Schneider, S Danzenbaecher, J Hinarejos, M Richter, C Laubschat

Variations of the photoionization cross-section of valence states as a function of interatomic distance are studied by means of atomic and solid-state density functional approaches and compared with photoemission data. In contrast to the free atom case, a

Surface Sensitivity of Auger-Electron Spectroscopy and X-Ray Photoelectron Spectroscopy

August 9, 1999

Author(s)

Cedric J. Powell, E Jablonski, I Tilinin, David R. Penn

A convenient measure of surface sensitivity in Auger-electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) is the mean escape depth (MED). If the effects of elastic-electron scattering are neglected, the MED is equal to the electron

Vibrationally-Resolved Sum-Frequency Generation With Broad Bandwidth Infrared Pulses

October 15, 1998

Author(s)

Lee J. Richter, T Petralli-Mallow, John C. Stephenson

We present a novel procedure for vibrationally-resolved sum-frequency generation (SFG) in which a broad-bandwidth IR pulse is mixed with a narrow-bandwidth visible pulse. The resultant SFG spectrum is dispersed with a spectrograph and detected in parallel

Dynamical Screening at the Metal-semiconductor Interface and Excitonic Superconductivity

March 27, 1997

Author(s)

Oleg Zakharov, Marvin Cohen, Steven G. Louie, David R. Penn

We examine the possibility of excitonic superconductivity at a metal-semiconductor interface. An ab initio RPA calculation of the screened Coulomb electron-electron interaction is performed for the silicon-jellium multilayer model. The superconducting

Generalized Slater-Koster Method for Fitting Band Structures

January 1, 1997

Author(s)

Mark D. Stiles

A tight-binding procedure is presented for fitting electronic band structures of crystals. It is based on a fully automated method of determining all possible independent matrix elements for arbitrary crystal structures. A fit, using this method, for the

Theory of the Cross Sections for Inelastic Scattering of Electrons by Core Level Excitations in Solids

January 1, 1997

Author(s)

David R. Penn, Charles W. Clark, Cedric J. Powell, T Fulop, Shigeo Tanuma

Total-dielectric-function Approach to Electron and Phonon Response in Solids

January 1, 1995

Author(s)

David R. Penn, S Lewis, Marvin Cohen

The interaction between two test charges, the response of a solid to an external field, and the normal modes of the solid can be determined from a total dielectric function that includes both electronic and lattice polarizabilities as well as local-field

Calculations of Electron Inelastic Mean Free Paths (IMFPs) V. Data for 14 Organic Compounds over the 50-2000 eV Range

September 14, 1994

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We report calculations of electron inelastiv mean free paths (IMFPs) of 50-2000 eV electrons for a group of 14 organic compounds: 26-n-paraffin, adenine, β-carotene, bovine plasma albumin, deoxyribonucleic acid, diphenylhexatriene, guanine, kapton

Effects of Elastic and Inelastic Electron-scattering on Quantitative Surface Analysis by A.E.S. and X.P.S

January 1, 1994

Author(s)

Cedric J. Powell, E Jablonski, Shigeo Tanuma, David R. Penn

A review is given that describes the complications due to elastic and inelastic electron scattering in quantitative surface analyses by Auger-electron spectroscopy and x-ray photoelectron spectroscopy. Four principal topics are addressed. First, the simple

Electron Inelastic Mean Free Paths in Organic Materials Especially for Polyethylene and Guanine

January 1, 1994

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We have calculated the electron inelastic mean free paths (IMFPs) in the range 50-2000 eV for 14 different organic compounds using the Penn algorithm. We report here mainly the calculated values of IMFPs for polyethylene and guanine, because their

Calculations of Electron Inelastic Mean Free Paths (IMFPs) IV. Evaluation of Calculated IMFPs and of the Predictive IMFP Formula Tpp-2 for Electron Energies between 50 and 2000 eV

January 1, 1993

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We have made additional evaluations of the electron inelastic mean free paths (IMFPs) and of the predictive IMFP formula TPP-2 presented in papers II and III of this series. Comparisons have been made with other formulae for the IMFPs and electron

Inverse Isotope Effects and Models for High-Tc Superconductivity

January 1, 1993

Author(s)

David R. Penn, Marvin Cohen, V Crespi

A model for high-temperature superconductivity with a mass-independent electronic mechanism in conjunction with a moderate amount of electron-phonon coupling has previously been shown to be inconsistent with experimental constraints on T c, the isotope

Use of Sum Rules on the Energy-Loss Function for the Evaluation of Experimental Optical Data

January 1, 1993

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We present an evaluation of optical data for Al, Si, Ti, Mo, W, and Ir based on two sum rules for the energy-loss function, the familiar f-sum rule and another sum rule based on a limiting form of the Kramers-Kronig integral. These sum rules were used to

Effects of Broadening on the BCS Theory in the Presence of Van Hove Singularities

January 1, 1992

Author(s)

David R. Penn, Marvin Cohen

There have been recent suggestions that high-Tc superconductivity can be understood in terms of conventional BCS theory if there is a logarithmic Van Hove singularity in the electron density of states near the Fermi energy as suggested by band theory. We

Inelastic Mean Free Paths of Low Energy Electrons in Solids

January 1, 1992

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We present a summary of recent calculations of the electron inelastic mean free paths (IMFPs) of 50-2000 eV electrons in a group of 27 elements and 15 inorganic compounds. These calculations are based in part on experimental optical data to represent the

Photo-Induced Resonant Tunneling Treated by the Extended Transfer Hamiltonian Method

January 1, 1992

Author(s)

S Apell, David R. Penn

A method, originally due to Heitler, is utilized to extend the transfer Hamiltonian description to resonant tunneling for the purpose of calculating transition probabilities and general frequency response characteristics of coupled systems. The scanning

Anharmonic Phonons and the Isotope Effect in Superconductivity

January 1, 1991

Author(s)

V Crespi, Marvin Cohen, David R. Penn

Anharmonic interionic potentials are examined in an Einstein model to study the unusual isotope-effect exponents for the high-T(c) oxides. The mass dependences of the electron-phonon coupling constant λ and the average phonon frequency square-root <ω2> are

Calculations of Electron Inelastic Mean Free Paths II. Data for 27 Elements over the 50-2000 eV Range

January 1, 1991

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We report calculations of electron inelastic mean free paths (IMFPs) for 50-2000 eV electrons in a group of 27 elements (C, Mg, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, Au and Bi). This work extends our

Calculations of Electron Inelastic Mean Free Paths III. Data for 15 Inorganic Compounds over the 50-2000 eV Range

January 1, 1991

Author(s)

Shigeo Tanuma, Cedric J. Powell, David R. Penn

We report calculations of electron inelastic mean free paths (IMFPs) of 50-2000 eV electrons in a group of 15 inorganic compounds (Al 2O 3, GaAs, GaP, InAs, InP, InSb, KCl, LiF, NaCl, PbS, PbTe, SiC, Si 3N 4, SiO 2, ZnS). As was found in similar

Experimental Constraints on Some Mechanisms for High-Temperature Superconductivity

January 1, 1991

Author(s)

I Barbee, Marvin Cohen, David R. Penn

Since its discovery, many mechanisms have been suggested to explain the phenomenon of high-temperature superconductivity in oxides. We propose that experimental data, along with theoretical models, can place constraints on or exclude many of these

Limitations on a Combined Phonon -- Non-Phonon Mechanism for Superconductivity Bi 2 Sr 3 Ca 1 Cu 2 O x

January 1, 1991

Author(s)

I Barbee, Marvin Cohen, David R. Penn

Despite the large number of theories proposed to explain high-temperature superconductivity, no clear explanation of its origin exists. Experimental data such as the isotope effect α and the gap ratio 2Δ}/k bT c can be used to constrain possible models for

Spin Polarized Metastable Atom He De-excitation, Theory

January 1, 1991

Author(s)

David R. Penn, S Apell

Metastable spin-polarized He* atoms incident on a Ni surface undergo deexcitation in a process which yields electron from the Ni. The number produced is observed to depend on the relative spin of teh Ni and the He* atoms. The normalized difference in the

Extended Transfer Hamiltonian Method for Resonant Tunneling

December 10, 1990

Author(s)

S Apell, E Albertsson, David R. Penn