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Search Publications by: Thomas J. Silva (Fed)

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Displaying 126 - 150 of 270

Temperature dependence of spin-torque-driven self-oscillators

October 15, 2009
Author(s)
William H. Rippard, Matthew R. Pufall, Thomas Cecil, Thomas J. Silva, Stephen E. Russek, M. L. Schneider
We have measured the temperature dependence of spin-torque-driven self-oscillations in point-contact nanooscillators for both in-plane and out-of-plane applied fields. We find that the linewidth for both field geometries is qualitatively similar. In the

Microwave assisted magnetization reversal in single domain nanoelements

July 6, 2009
Author(s)
Hans T. Nembach, Hans Bauer, Justin M. Shaw, Michael Schneider, Thomas J. Silva
We studied the microwave assisted magnetic reversal in 65×71 nm 2 elliptical Ni 80Fe 20 nanomagnets with a thickness of 10 nm. Hysteresis curves were measured by magneto-optical Kerr effect for a range of microwave frequencies and amplitudes. We observe a

Time domain measurement of phase noise in a spin torque oscillator

May 13, 2009
Author(s)
Mark W. Keller, Anthony B. Kos, Thomas J. Silva, William H. Rippard, Matthew R. Pufall
We measure phase noise from the zero crossings of the voltage vs. time waveform of a spin torque nanocontact oscillating in a vortex mode. The power spectrum of the phase noise varies with Fourier frequency f as 1/f 2, consistent with frequency

Collimated spin wave beam generated by a single layer, spin torque nanocontact

April 1, 2008
Author(s)
Mark Hoefer, Thomas J. Silva, M D. Stiles
A model of spin-torque-induced magnetization dynamics based on semiclassical spin diffusion theory for a single-layer nanocontact in presented. The model incorporates effects due to the current-induced Oersted field and predicts the generation of a variety

Developments in nano-oscillators based upon spin-transfer point-contact devices

December 31, 2007
Author(s)
Thomas J. Silva, William H. Rippard
We review the current status of research on microwave nano-oscillators that utilize spin transfer devices with point-contact geometry, with an emphasis on the open questions that still prevent our full understanding of device properties. In particular, we

Experimental determination of the inhomogeneous contribution to linewidth in Permalloy films using a time-resolved magneto-optic Kerr effect microprobe

September 12, 2007
Author(s)
Michael Schneider, Thomas Gerrits, Anthony B. Kos, Thomas J. Silva
We adapted a time-resolved magneto-optic microprobe for use with the pulsed inductive microwave magnetometer apparatus, allowing us to measure the magnetization dynamics of a thin Permalloy film at micrometer and millimeter length scales under exactly the

Field-free ringing of nanomagnets

July 1, 2007
Author(s)
Thomas J. Silva
Ever since William Gilbert's 16th century treatise "De Magnete," it has been known that magnetic fields can be used to manipulate the magnetic orientation of ferromagnets. This has been the foundation for electronic applications of magnetic materials for

Spin Torque for Dummies

January 6, 2007
Author(s)
Thomas J. Silva
I will present a stripped down presentation on the fundamental mechanisms that give rise to spin torque effects. This presentation will assume the audience has little or no background in this fascinating and rapidly expanding field. We will start with an