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Displaying 76 - 100 of 240

New Magnetic Phases of bcc-Co Thin Films

January 1, 2005
Author(s)
T Monchesky, John Unguris
We have been able to observe two new magnetic phases of ultrathin Co by growing atomically well ordered Co films on cleaved GaAs(110) substrates. For a Co thickness less than 3.4 monolayers (ML), we find a ferromagnetically dead layer associated with the

Zigzag-shaped magnetic sensors

December 13, 2004
Author(s)
Fabio C. da Silva, Willard C. Uhlig, Anthony B. Kos, Susan A. Schima, Joe Aumentado, John Unguris, David P. Pappas
Magnetism in zigzag-shaped thin-film elements is investigated using scanning electron microscopy with polarization analysis, magnetotransport measurements, and micromagnetic simulations. We find that the angle of magnetization alternates along the length

Observation of a geometrically constrained domain wall in epitaxial FCC Co small disks

May 1, 2004
Author(s)
C Vaz, L Lopez-Diaz, M Klaui, J Bland, T Monchesky, John Unguris, Z Cui
The magnetic nanostructure of epitaxial FCC Co/Cu(0 0 1) circular elements (1.7 m in diameter) has been imaged with scanning electron microscopy with polarization analysis. A closed flux configuration (quadrant configuration) is observed for most of the

Zigzag Shaped Magnetic Sensors

January 1, 2004
Author(s)
S da, Willard C. Uhlig, A Kos, Joe Aumentado, Michael J. Donahue, John Unguris, David P. Pappas
Magnetism in zigzag shaped thin film elements is investigated using scanning electron microscopy with polarization analysis, magneto-transport measurements, and micromagnetic simulations. We find that the angle of magnetization alternates along the length

Electron Beam Stimulated Spin Reorientation

May 15, 2003
Author(s)
T L. Monchesky, John Unguris, Robert Celotta
Using Scanning Electron Microscopy with Polarization Analysis (SEMPA), we observed the electron beam induced switching of the magnetic state of epitaxial single-crystal Fe(110) films grown on atomically flat cleaved GaAs(110). For low film thickness the

Direct Observation of Remanent Magnetic States in Epitaxial fcc Co Small Disks

April 1, 2003
Author(s)
C Vaz, L Lopez-Diaz, M Klaui, J Bland, T Monchesky, John Unguris, Z Cui
The magnetic nanostructure of epitaxial fcc Co/Cu(001) circular elements (1.7υm in diameter) has been imaged with scanning electron microscopy with polarization analysis. The disks are obtained by ultrahigh vacuum deposition of the metal films onto a

Magnetic Domain Imaging of Spintronic Devices

January 1, 2003
Author(s)
Robert Celotta, John Unguris, Daniel T. Pierce
A description of high resolution magnetic domain imaging methods of specific use in observing magnetic structure in magneto electronic, i.e., spintronics.

The Magnetic Order of Cr in Fe/Cr/Fe(001) Trilayers

January 1, 2001
Author(s)
Daniel T. Pierce, John Unguris, Robert Celotta, Mark D. Stiles
The temperature dependence of the short period oscillatory coupling in Fe/Cr/Fe(001) whisker trilayers, when analyzed in light of recent theory, provides strong evidence that incommensurate spin density wave antiferromagnetic order is induced in the Cr

Non-collinear Exchange Coupling in Fe/Mn/Fe(001): Insight from Scanning Tunneling Microscopy

December 1, 2000
Author(s)
Daniel T. Pierce, Angela Davies, Joseph A. Stroscio, D Tulchinsky, John Unguris, Robert Celotta
The film growth and morphology of epitaxial Mn films grown on Fe(001) single crystal whiskers measured with scanning tunneling microscopy (STM) provides insight into the mechanism of interlayer exchange coupling in Fe/Mn/Fe(001) trilayers. The proximity

Techniques to Measure Magnetic Domain Structures

September 11, 2000
Author(s)
Robert Celotta, John Unguris, Michael H. Kelley, Daniel T. Pierce
A summary of the current techniques for magnetic domain imaging of materials, including the practical aspects of each technique, the requirements on the sample, the specimen modification allowed and the problems normally encountered. References to more

Magnetic Depth Profiling Co/Cu Multilayers to Investigate Magnetoresistance

May 1, 2000
Author(s)
John Unguris, D Tulchinsky, Michael H. Kelley, Julie A. Borchers, Joseph A. Dura, Charles F. Majkrzak, S. Y. Hsu, R Loloee, W Pratt, J Bass
The magnetic microstructure responsible for the metastable high resistance state of weakly coupled, as-prepared [Co(6nm)/Cu(6nm)] 20 multilayer was analyzed using polarized neutron reflectivity (PNR) and scanning electron microscopy with polarization