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Search Publications by: Mark D. Stiles (Fed)

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Displaying 176 - 200 of 202

Growth of Giant Magnetoresistance Spin Valves Using Pb and Au as Surfactants

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz
We have investigated the use of Pb and Au as surfactants in an attempt to achieve smoother and sharper interfaces in three types of giant magnetoresistance (GMR) spin valve multilayers: symmetric spin valves, bottom spin valves, and top spin valves. The

Growth of GMR Spin Valves using Indium as a Surfactant

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael
We have investigated the use of In as a surfactant to achieve smoother interfaces in spin-valve multilayers of the general type: FeMn/Ni 80Fe 20/Co/Cu/Co/Ni 80Fe 20/glass. The coupling field is reduced from 0.8 to 0.3 mT, presumably by suppressing

Low-temperature Growth of GMR Spin Valves

January 1, 1996
Author(s)
William F. Egelhoff Jr., R Misra, T Ha, Y Kadmon, Cedric J. Powell, Mark D. Stiles, Robert McMichael, Lawrence H. Bennett, C Lin, J Sivertsen, J Judy
We have investigated the dependence of the giant magnetoresistance (GMR) effect, the coercivity, the coupling field, and the resistivity on film deposition at low-substrate temperatures (150 K) in spin valve multilayers of the general type: FeMn/Ni 80Fe 20

Magnetization Reversal in Ultrathin Films with Monolayer-Scale Surface Roughness

January 1, 1996
Author(s)
A Moschel, A Zangwill, R Hyman, Mark D. Stiles
The intrinsic anisotropy of nominally flat, ultrathin ferromagnetic films typically is augmented by a uniaxial anisotropy at step edges. We report model calculations of hysteresis for such systems with in-plane magnetization and monolayer scale roughness

Optimizing the GMR of Symmetric and Bottom Spin Valves

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz, T Anthony, J Brug
We have attempted to optimize the values of the giant magnetoresistance in symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO (achieving 23.4%) and in bottom spin valves of the type Co/Cu/Co/NiO (achieving 17.0%), the largest values ever reported for

Oscillatory Exchange Coupling in Fe/Cr Multilayers

January 1, 1996
Author(s)
Mark D. Stiles
First-principles calculations of the reflection probabilities for Fermi surface electrons at Cr/Fe interfaces are used to compute the strength of the oscillatory exchange coupling in Cr/Fe multilayers. These calculations show that critical spanning vectors

The Trade-off Between Large GMR and Small Coercivity in Symmetric Spin Valves

January 1, 1996
Author(s)
William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz
We have investigated the use of various alloys as substitutes for pure Co in the center film of symmetric spin valves of the type NiO/Co/Cu/Co/Cu/Co/NiO. The aim of this work is to identify magnetic materials that exhibit smaller coercivities than pure Co

Coarsening of Unstable Surface Features During Fe(001) Homoepitaxy

January 1, 1995
Author(s)
Joseph A. Stroscio, Daniel T. Pierce, Mark D. Stiles, A Zangwill, L Sander
The evolution of the surface profile during homoepitaxial growth of Fe(001) is studied by scanning tunnelling microscopy and reflection high energy electron diffraction. The observed morphology exhibits a non-self affine collection of mound-like features

Magnetoresistance Values Exceeding 21 Percent in Symmetric Spin Valves

January 1, 1995
Author(s)
William F. Egelhoff Jr., T Ha, R Misra, Y Kadmon, J Nir, Cedric J. Powell, Mark D. Stiles, Robert McMichael, C Lin, J Sivertsen, J Judy, K Takano, A Berkowitz, T Anthony, J Brug
We report values of the giant magnetoresistance (GMR) effect exceeding 21% in symmetric spin valves, the highest values ever reported for such structures. The key elements in this achievement are the use of a Co/Cu/Co/Cu/Co multilayer in which the center

STM Studies of GMR Spin Valves

January 1, 1995
Author(s)
R Misra, T Ha, Y Kadmon, Cedric J. Powell, Mark D. Stiles, Robert McMichael
We have investigated the surface roughness and the grain size in giant magnetoresistance (GMR) spin valve multilayers of the general type: FeMn/Ni 80Fe 20/Co/Cu/Co/Ni 80 Fe 20 on glass and aluminum oxide substrates by scannin tunneling microscopy (STM)

Exchange Coupling in Magnetic Heterostructures

January 1, 1993
Author(s)
Mark D. Stiles
Many structures consisting of magnetic layers separated by a nonmagnetic spacer layer show an oscillatory exchange coupling. This behavior is explained in terms of a simple model that shows that the Fermi surface of the spacer layer material is responsible

Theory of Photo-induced Resonant Tunneling in Heterojunctions

January 1, 1992
Author(s)
S Apell, David R. Penn, Mark D. Stiles
The theoretical basis for understanding photo-assisted resonant tunneling is generally taken to be the theory by Tien and Gordon [Phys. Rev. 129, 647 (1963)] in which the effect of a photon field on an energy state is to create sidebands at multiples of

Kinematic Theory of BEEM Spectroscopy of Silicon-Silicide Interfaces

January 1, 1991
Author(s)
Mark D. Stiles, D Hamann
The electronic structure of the materials being measured has a strong effect on the spectroscopy of the interface between them measured by ballistic electron emission microscopy (BEEM). Specific calculations for CoSi 2/Si(111) and NiSi 2/Si(111) based on

Quantum Fluctuations and the Single Junction Coulomb Blockade

January 1, 1990
Author(s)
S Girvin, L Glazman, M Jonson, David R. Penn, Mark D. Stiles
We investigate the effect of quantum flucuations on the Coulomb blockade in a single tunnel junction coupled to its environment by a transmission line of arbitrary impedance Z (ω). The quantized oscillating modes of the transmission line are suddenly

Electron Transmission Through NiSi 2 -Si Interfaces

January 1, 1989
Author(s)
Mark D. Stiles, D Hamann
Calculations of electron transmission through epitaxial NiSi 2/Si(111) interfaces illustrate the versatality of a newloy developed first-principles technique. The transmission is poor and very dependent on the interface structure; of the electrons of

Coercivities Above 10 kOe in CoPd Superlattices

Author(s)
William F. Egelhoff Jr., Cedric J. Powell, L Gan, P J. Chen, H Ettedgui, D Tirosh, Robert D. McMichael, Mark D. Stiles, J Mallett, Alexander J. Shapiro, John E. Bonevich, J H. Judy, Erik B. Svedberg, A. E. Berkowitz
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

Suppressing of Unidirectional Coupling in Magnetic Tunnel Junctions by Preoxidation: Structural Studies

Author(s)
William F. Egelhoff Jr., Robert D. McMichael, Mark D. Stiles, Cedric J. Powell, John E. Bonevich, M Wormington, D S. Eastwood, B K. Tanner
Pre-oxidation of the bottom electrode prior to deposition of Al_{2}O_{3} or MgO is very effective as a general approach to suppressing the unidirectional coupling that is commonly observed in magnetic tunnel junctions. In this paper, we report structural