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: Robert D. McMichael (Assoc)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 151 - 175 of 314

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

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

Ferromagnetic Resonance Linewidth Models for Perpendicular Media

June 1, 2004
Author(s)
Robert D. McMichael
Ferromagnetic resonance linewidth in pendicular recording media is modeled with inhomogeneous uniaxial anisotropy field H u and with tilting of the easy axes from the film normal. The linewidth is calculated using both a local resonance model 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

Structure and Magnetic Properties of Electrodeposition Co on n-GaAs (001)

September 19, 2003
Author(s)
A X. Ford, John E. Bonevich, Robert D. McMichael, Mark D. Vaudin, Thomas P. Moffat
Co thin films have been electrodeposited on n-type (001) GaAs. The structure and texture of the films were investigated using x-ray diffraction (XRD) and transmission electron microscopy (TEM) while the magnetic properties were examined using a vibrating

Localized Ferromagnetic Resonance in Inhomogeneous Thin Films

June 1, 2003
Author(s)
Robert McMichael, A Kunz, D J. Twisselmann
The effect of sample inhomogeneity on the ferromagnetic resonance line width is determined by diagonalization of a spin wave Hamiltonian for ferromagnetic thin films with inhomogeneities. The resonance line broadening results from the distribution of the

Magnetic and Structural Characterization and Ferromagnetic Resonance Study of Thin Film HITPERM Soft Magnetic Materials for Data Storage Applications

May 1, 2003
Author(s)
Hideyuki Okumura, D J. Twisselmann, Robert McMichael, M Q. Huang, Y N. Hsu, D E. Laughlin, M E. McHenry
HITPERM/SiO 2 single and multilayer thin films have been produced using a target composition of (Fe 70Co 30) 88}Zr 7}B 4}Cu 1}. The as-deposited HITPERM film contains small bcc (or B2) nanocrystals of volume fraction less than 10% surrounded by an

Magnetization Dynamics Modeled in Magnetic Thin Films

March 1, 2003
Author(s)
Robert D. McMichael
One of the challenges facing designers of high data rate computer hard drives and magnetic memory chips is that for most magnetic metals, it typically takes a fewnanoseconds for the magnetization to come to rest after it has been switched or bumped by a