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Search Publications by: Stephen E. Russek (Fed)

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Displaying 126 - 150 of 337

Origins of switching field distributions in perpendicular magnetic nanodot arrays

January 19, 2007
Author(s)
Justin Shaw, William Rippard, Stephen E. Russek, Tim Reith, Charles M. Falco
We studied the reversal properties of perpendicularly magnetized Co/Pd nanodots from 100 to 50 nm in diameter fabricated using electron beam lithography. Polycrystalline Co/Pd multilayers show considerable differences in the switching field distribution

Manipulation of magnetic particles by patterned arrays of magnetic spin-valve traps

December 20, 2006
Author(s)
Elizabeth Mirowksi, John M. Moreland, Stephen E. Russek, Michael J. Donahue
A novel magnetic for microfluidic manipulation of magnetic particles is discussed. The particles are confined by an array of magnetic spin valves with bistable ferromagnetic "ON" and antiferromagnetic "OFF" net magnetization states. The switchable fringing

Dynamic Lorentz Microscopy of Micromagnetic Structure in Magnetic Tunnel Junctions

November 20, 2006
Author(s)
Justin Shaw, R.H. Geiss, Stephen E. Russek
Lorentz microscopy was used to study the micromagnetic structure and magnetization reversal in magnetic tunnel junctions (MTJs) fabricated with different processing conditions including a preoxidation process. The authors find that the free layer in a MTJ

Experimental separability of channeling giant magnetoresistance in Co/Cu/Co

July 13, 2006
Author(s)
William E. Bailey, Stephen E. Russek, X.-G. Zhang, W. H. Butler
The magnitude of the electronic channeling contribution is a significant open issue in the understanding of giant magnetoresistance (GMR). We show that for the technologically important system Co/Cu/Co, channeling GMR can be isolatedand quantified

Tailored Nanoscale Contrast Agents for Magnetic Resonance Imaging

December 30, 2005
Author(s)
Alexander J. Barker, Brant Cage, Stephen E. Russek, Ruchira Garg, R Shandas, Conrad Stoldt
Two potential molecular imaging vectors are investigated for material properties and magnetic resonance imaging (MRI) contrast improvement. Monodisperse magnetite (Fe 3O 4) nanocrystals ranging in size from 7 to 22 nm are solvothermally synthesized by

Ultraviolet Laser Damage of Carbon Nanotube Coatings on Thermal Detector Platforms

November 14, 2005
Author(s)
Darryl A. Keenan, Natalia Varaksa, Anne Dillon, Chaiwat Engtrakul, Stephen E. Russek, John H. Lehman
We have initiated a program to demonstrate the next generation of optical detector coatings using carbon nanotubes (CNTs). These coatings have been used on a variety of detector platforms for laser power and energy measurement standards. These coatings

Mutual phase-locking of microwave spin torque nano-oscillators

September 15, 2005
Author(s)
Shehzaad F. Kaka, Matthew Pufall, William Rippard, Thomas J. Silva, Stephen E. Russek, Jordan A. Katine
The spin torque effect that occurs in nanometre-scale magnetic multilayer devices can be used to generate steady- state microwave signals in response to a d.c. electrical current. This establishes a new functionality for magneto-electronic structures that

Resonant microwave power absorption and relaxation of the energy levels of the molecular nanomagnet Fe 8 using superconducting quantum interference device-based magnetometry

August 15, 2005
Author(s)
Brant Cage, Stephen E. Russek, David Zipse, Micah North, Naresh S. Dalal
Energy levels and saturation of molecular nanomagnet Fe 8 crystals were investigated using a 95 and 141 GHz electron paramagnetic resonance (EPR) technique based on a standard superconducting quantum intererence device (SQUID) magnetometer. The technique

Injection Locking and Phase Control of Spin Transfer Nano-Oscillators

August 5, 2005
Author(s)
William Rippard, Matthew Pufall, Shehzaad F. Kaka, Thomas J. Silva, Stephen E. Russek, Jordan A. Katine
We have directly measured phase locking of spin transfer oscillators to an injected ac current. The oscillators lock to signals up to several hundred megahertz away from their natural oscillation frequencies, depending on the relative strength of the input