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Search Publications by: Thomas J. Silva (Fed)

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Displaying 101 - 125 of 135

Different Dynamic and Static Magnetic Anisotropy in Thin Permalloy Films

July 6, 2003
Author(s)
Radek Lopusnik, John P. Nibarger, Thomas J. Silva, Zbigniew J. Celinski
The values of uniaxial anisotropy Hk in thin polycrystalline Permalloy films measured by static and dynamic methods differ by as much as a factor 1.5. The anisotropy obtained with a pulsed inductive microwave magnetometer in 2.5-100 nm thick Permalloy

Cyrogenic pulsed inductive microwave magnetometer

May 15, 2003
Author(s)
Anthony B. Kos, John P. Nibarger, Radek Lopusnik, Thomas J. Silva, Zbigniew J. Celinski
A cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film materials at low temperatures and microwave frequencies. The system is contained inside a 20-cm-dia ultrahigh vacuum chamber and cooled by a

Pulsed inductive microwave magnetometer

October 1, 2002
Author(s)
Anthony B. Kos, Thomas J. Silva, Pavel Kabos
We describe the apparatus, software, and measurement procedures for a pulsed inductive microwave magnetometer (PIMM). PIMM can measure the dynamical properties of materials used in recording heads for magnetic storage applications and it can be used as a

Measurement of Dynamic Properties in Thin-Films

December 1, 2001
Author(s)
Thomas J. Silva
I present a summary of the various techniques available for the determination of response times in magnetic recording head materials. In addition, I derive useful equations for the interpretation of data in the context of the Landau-Lifshitz-Gilbert

High Frequency Measurements of CoFeHfO Thin Films

July 1, 2001
Author(s)
Stephen E. Russek, Pavel Kabos, Thomas J. Silva, Fred B. Mancoff, D Wang, Z. T. Qian, J. M. Daughton
High frequency measurements of the transverse susceptibility and damping constant of CoFeHfo thin films have been made over a frequency range of 0.1 GHz to 6 GHz as a function of film resistivity, thickness, and temperature. The films show relatively low

Metastable States in Large Angle Magnetization Rotations

September 1, 2000
Author(s)
Pavel Kabos, Shehzaad F. Kaka, Stephen E. Russek, Thomas J. Silva
Large angle rotations were studied in Permalloy thin films and spin valve devices. It is shown that edge effects or inhomogeneities strongly influence the magnetization behavior under certain initial conditions. Complicated intermediate states can form

Vectorial second-harmonic magneto-optic kerr effect measurement

May 1, 2000
Author(s)
Pavel Kabos, Anthony B. Kos, Thomas J. Silva
A significant modification of an existing experimental technique based on the second-harmonic magneto-optical Kerr effect (SH-MOKE) is introduced. With a p-polarized pumping optical wave incident upon a magnetic film, the transverse component of

Coherent Control of Precessional Dynamics in Thin Film Permalloy

April 1, 2000
Author(s)
T. M. Crawford, Pavel Kabos, Thomas J. Silva
We demonstrate a method of eliminating overshoot and ringing in magnetizaiton dynamics when the system bandwidth includes the intrinsic ferromagnetic resonance (FMR). The method employsstaggered step excitation for the cancellation of FMR oscillations

Nanosecond Magnetization Reversal in High Coercivity Thin Films

January 1, 2000
Author(s)
N D. Rizzo, Thomas J. Silva, Anthony B. Kos
We used a wide-field Kerr microscope to measure magnetization reversal in high coercivity thin film media that were subjected to nanosecond field pulses. Coplanar waveguides were used as a field source. Two different samples of CoCr 10Ta 4 were measured