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Search Publications by: Cedric J Powell (Assoc)

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Displaying 151 - 175 of 190

Optimizing the GMR of Symmetric and Bottom Spin Valves

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz, T Anthony, J Brug
We have attempted to optimize the values of the giant magnetoresistance in symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO (achieving 23.4%) and in bottom spin valves of the type Co/Cu/Co/NiO (achieving 17.0%), the largest values ever reported for

The Trade-off Between Large GMR and Small Coercivity in Symmetric Spin Valves

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz
We have investigated the use of various alloys as substitutes for pure Co in the center film of symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO. The aim of this work is to identify magnetic materials that exhibit smaller coercivities than pure Co

Magnetoresistance Values Exceeding 21 Percent in Symmetric Spin Valves

January 1, 1995
Author(s)
William F. Egelhoff Jr., T Ha, R Misra, Y Kadmon, J Nir, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz, T Anthony, J Brug
We report values of the giant magnetoresistance (GMR) effect exceeding 21% in symmetric spin valves, the highest values ever reported for such structures. The key elements in this achievement are the use of a Co/Cu/Co/Cu/Co multilayer in which the center

STM Studies of GMR Spin Valves

January 1, 1995
Author(s)
R Misra, T Ha, Y Kadmon, Cedric J. Powell, Mark D. Stiles, Robert McMichael
We have investigated the surface roughness and the grain size in giant magnetoresistance (GMR) spin valve multilayers of the general type: FeMn/Ni 80Fe 20/Co/Cu/Co/Ni 80 Fe 20 on glass and aluminum oxide substrates by scannin tunneling microscopy (STM)

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

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

Electron Inelastic Mean Free Paths in Solids at Low Energies

January 1, 1990
Author(s)
Shigeo Tanuma, Cedric J. Powell, David R. Penn
We have calculated electron inelastic mean free paths (IMFPs) for 50-200 eV electrons in 31 materials (27 elements and 4 compounds). These calculations extend those previously reported for 200-2000 eV electrons in the same materials but avoid an

Material Dependence of Electron Inelastic Mean Free Paths at Low Energies

January 1, 1990
Author(s)
Shigeo Tanuma, Cedric J. Powell, David R. Penn
We have calculated electron inelastic mean free paths (IMFPs) for 50-2000 eV electrons in 31 materials (27 elements and 4 compounds). We present and discuss in this paper IMFP data for aluminum and gold in the 50-2000 ev Range. Substantial differences are

Quantitative Surface Analysis by Electron Spectroscopy

April 1, 1978
Author(s)
Cedric J. Powell
An overview is given of a new cooperative project under the Implementing Agreement between the Technology Administration, U.S. Department of Commerce, and the Agency of Industrial Science and Technology, Japanese Ministry of International Trade and

Surface Analysis by Electron Spectroscopy at High Pressures

March 1, 1978
Author(s)
Cedric J. Powell
Surface analyses are now made by techniques such as Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS), and appearance potential spectroscopy (APS). These techniques utilize low-energy electrons and have high surface sensitivity but

Auger Electron Spectroscopy

February 1, 1978
Author(s)
Cedric J. Powell
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

Quantitative Surface Analysis by X-Ray Photoelectron Spectroscopy

January 1, 1978
Author(s)
Cedric J. Powell
Measurements have been made of the relative intensities of the principal features in X-ray photoelectron spectra of indium, lead, and aluminum oxide and compared with those expected from a simple model for the photoemission process. Systematic effects in

Surface Characterization: Present Status and the Need for Standards

January 1, 1978
Author(s)
Cedric J. Powell
A summary is given of the present status and use of surface-characterization measurements in the United States. Attention is primarily devoted to those properties needed to characterize a solid surface, specifically the determination of surface composition
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