U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Cedric J Powell (Assoc)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 51 - 75 of 194

Experimental Determination of Electron Inelastic Mean Free Paths in 13 Elemental Solids in the 50 eV to 5000 eV Energy Range by Elastic-Peak Electron Spectroscopy

May 1, 2005
Author(s)
S Tanuma, T Shiratori, Tetsuya Kimura, K Goto, S Ichimura, Cedric J. Powell
We have determined electron inelastic mean free paths (IMFPs) in C (graphite), Si, Cr, Fe, Cu, Zn, Ga, Mo, Ag, Ta, W, Pt and Au by elastic-peak electron spectroscopy (EPES) using Ni as a reference material for electron energies between 50 eV and 5000 eV

Monte Carlo Strategies for Simulations of Electron Backscattering from Surfaces

May 1, 2005
Author(s)
Aleksander Jablonski, Cedric J. Powell, S Tanuma
Reliable algorithms for simulation of electron trajectories in solids are needed for quantification of Auger electron spectroscopy, particularly for determination of the backscattering factor (BF). The computational schemes for this purpose should be

Origin of Exchange Decoupling Effects in High-Coercivity Air-Annealed CoPd Multilayers

May 1, 2005
Author(s)
William F. Egelhoff Jr., Robert McMichael, J Mallett, Alexander J. Shapiro, Cedric J. Powell, John E. Bonevich, J H. Judy, J H. Thomas, Erik B. Svedberg
We have achieved excellent exchange decoupling of grains in CoPd multilayers by annealing in air at 300 C. Samples exhibit a slope in the hysteresis loop close to 1.0, nucleation fields as large as 1.1 T, and coercivities as large as 1.6 T. These are among

Artifacts That Mimic Ballistic Magnetoresistance

February 1, 2005
Author(s)
William F. Egelhoff Jr., L Gan, H Ettedgui, Y Kadmon, Cedric J. Powell, P J. Chen, Alexander J. Shapiro, Robert McMichael, J Mallett, Thomas P. Moffat, Mark D. Stiles, Erik B. Svedberg
We have investigated the circumstances underlying recent reports of very large values of ballistic magntoresistance (BMR) in nanocontacts between magnetic wires. We find that the geometries used are subject to artifacts due to motion of the wires that

Interface Intermixing and In-Plane Grain Size in Aluminum-Transition Metal Bilayers

December 1, 2004
Author(s)
J D. Buchanan, T P. Hase, B K. Tanner, Cedric J. Powell, William F. Egelhoff Jr.
The correlation between grain size and intermixing in sputter deposited bilayers of the form X/Al and Al/X has been investigated by in-plane grazing incidence x-ray diffraction. We find a strong correlation between grain size and intermixing at the

Differential Cross Sections for Elastic Scattering of Electrons by Atoms and Solids

July 1, 2004
Author(s)
Aleksander Jablonski, Francesc Salvat, Cedric J. Powell
Differential cross sections (DCSs) for elastic scattering of electrons by neutral atoms are extensively used in studies of electron transport in solids and liquids. A new NIST database has recently been released with DCSs calculated from a relativistic

Summary of ISO/TC 201 Technical Report: ISO/TR 19319: 2003 Surface Chemical Analysis Auger Electron Spectroscopy and X-Ray Photoelectron Spectroscopy Determination of Lateral Resolution, Analysis Area, and Sample Area Viewed by the Analyser

July 1, 2004
Author(s)
Cedric J. Powell
ISO Technical Report 19319 contains information on the determination of lateral resolution, analysis area, and sample area viewed by the analyser in surface analyses by Auger-electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). This

Artifacts in Ballistic Magnetoresistance Measurements

June 1, 2004
Author(s)
William F. Egelhoff Jr., L Gan, H Ettedgui, Y Kadmon, Cedric J. Powell, P J. Chen, Alexander J. Shapiro, Robert McMichael, J Mallett, Thomas P. Moffat, Mark D. Stiles, Erik B. Svedberg
We have studied the behavior of electrodeposited Ni and Fe nanocontacts in magnetic fields and the changes in resistivity (Δ}R) that occur. Metallic particles suspended in plating solution, created and collected from the electroplating bath of a

Artifacts in Ballistic Magnetoresistance Measurements

June 1, 2004
Author(s)
William F. Egelhoff Jr., L Gan, H Ettendgui, Y Kadmon, Cedric J. Powell, P J. Chen, Alexander J. Shapiro, Robert McMichael, J Mallett, Thomas P. Moffat, Mark D. Stiles
We have carried out an extensive search for credible evidence to support the existence of a ballistic magnetoresistance (BMR) effect in magnetic nanocontacts. We have investigated both thin-film and thin-wire geometries for both mechanically-formed and

Information Depth for Elastic-Peak Electron Spectroscopy

February 1, 2004
Author(s)
Aleksander Jablonski, Cedric J. Powell
We present a formalism for calculating the information depth (ID) for elastic-peak electron spectroscopy (EPES) in which a measurement is made of the intensity of elastically-backscattered electrons for an amorphous or polycrystalline material and a

Artifacts that mimic ballistic magnetoresistance

January 1, 2004
Author(s)
William F. Egelhoff Jr., L Gan, Erik B. Svedberg, Cedric J. Powell, Alexander J. Shapiro, Robert McMichael, J Mallett, Thomas P. Moffat, Mark D. Stiles
We have investigated the circumstances underlying recent reports of very large values of ballistic magnetoresistance (BMR) in nanocontacts between magnetic wires. We find that the geometries used are subject to artifacts due to motion of the wires that

Coercivities above 10 kOe in CoPd Superlattices

January 1, 2004
Author(s)
William F. Egelhoff Jr., Cedric J. Powell, L Gan, P J. Chen, H Ettendgui, D Tirosh, Robert McMichael, Mark D. Stiles, J Mallett, Alexander J. Shapiro, John E. Bonevich
We have achieved excellent grain isolation in CoPd superlattices by using 10 nm Au as both an underlayer and an overlayer and diffusing Au into the grain boundaries by annealing for approximately equal to} 30 min. at 300 degrees C. The grain isolation

Electron Effective Attenuation Lengths in Electron Spectroscopies

January 1, 2004
Author(s)
Aleksander Jablonski, Cedric J. Powell
An important measure of the opacity of a solid with respect to monoenergetic electrons in a solid is the effective attenuation length (EAL). However, there is much controversy in the literature concerning the definition of this parameter. It has been shown