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Displaying 51 - 75 of 120

Growth & Magnetic Oscillatory Exchange Coupling of Mn/Fe (001) and Fe/Mn/Fe (001)

January 1, 2000
Author(s)
D Tulchinsky, John Unguris, Robert Celotta
The magnetic ordering and the interlayer exchange coupling in Mn and Fe/Mn wedge structures grown epitaxially on Fe(001) whisker substrates were investigated using scanning electron microscopy with polarization analysis (SEMPA). In bare Mn/Fe(001) samples

SEMPA Imaging of Domain Dynamics in Amorphous Metals

January 1, 2000
Author(s)
A Gavrin, John Unguris
We show how Scanning Electron Microscopy with Polarization Analysis (SEMPA) may be used to observe domain wall motion in amorphous ferromagnetic ribbons commonly used in transformer cores. SEMPA images were obtained from both the smooth, air side of the

Exchange Coupling in Magnetic Multilayers Grown on Iron Whiskers

August 20, 1999
Author(s)
John Unguris, Robert Celotta, D Tulchinsky, Daniel T. Pierce
Meaningful tests of theoretical predictions of magnetic multilayer properties require the fabrication of multilayers with nearly the same atomic scale precision as the theoretical models. Multilayers grown epitaxially on single crystal Fe whisker

Observation of antiparallel magnetic order in weakly coupled Co/Cu multilayers

May 23, 1998
Author(s)
Julie Borchers, Joseph Dura, John Unguris, D Tulchinsky, Michael H. Kelley, Charles Majkrzak, S. Y. Hsu, R Loloee, W Pratt, J Bass
Polarized neutron reflectivity and scanning electron microscopy with polarization analysis are combined to determine the magnetic structure of Co(6 nm)/Cu(6 nm) multilayers. These data resolve a controversy regarding the low-field state of giant

Observations of Alloying in the Growth of Cr on Fe(001)

January 1, 1997
Author(s)
Angela Davies, Joseph A. Stroscio, Daniel T. Pierce, John Unguris, Robert Celotta
Using scanning tunneling microscopy, we observe the alloying of Cr with an Fe(001) substrate for various coverages at two temperatures. At low Cr coverage, the alloy consists of individual Cr impurities surrounded by Fe. Elemental identification is

Optically Isolated Current to Voltage Converter in an Electron Optics System

January 1, 1997
Author(s)
Alan H. Band, John Unguris
A simple, inexpensive, optically isolated current-to-voltage converter circuit has been developed for the measurement of bipolar currents in the range of 10 pA to 1 %A on the biased elements of an electron optics system at voltages up to 3.5 kV. The design

Scanning Electron Microscopy with Polarization Analysis (SEMPA)

January 1, 1997
Author(s)
John Unguris, M Scheinfein, Michael H. Kelley, A Gavrin, Robert Celotta, Daniel T. Pierce
Scanning Electron Microscopy with Polarization Analysis (SEMPA) is a technique for the high spatial resolution imaging of magnetic microstructure. It employs a Scanning Electron Microscope (SEM) to create a finely focused electron beam on the surface of a

Hot Electron Spin-Valve Effect in Coupled Magnetic Layers

January 1, 1994
Author(s)
Robert Celotta, John Unguris, Daniel T. Pierce
SEMPA observations of magnetic exchange coupling in the Fe/Ag/Fe, Fe/Au/Fe, and Fe/Cr/Fe systems reveal an intensity variation in the emitted secondary electron signal that depends only on whether the Fe layers are coupled in a ferromagnetic or

Influence of Cr Growth on Exchange Coupling in Fe/Cr/Fe(100)

January 1, 1994
Author(s)
Daniel T. Pierce, Joseph A. Stroscio, John Unguris, Robert Celotta
Scanning electron microscopy with polarization-analysis (SEMPA) measurements of the dependence of the oscillations of the exchange coupling in Fe/Cr/Fe(100) structures on the Cr growth temperature are correlated with the thickness fluctuations in Cr films

Oscillatory Exchange Coupling in Fe/Au/Fe(100)

January 1, 1994
Author(s)
John Unguris, Robert Celotta, Daniel T. Pierce
Scanning electron microscopy with polarization analysis was used to investigate the interlayer exchange coupling in Fe/Au/Fe(100) sandwich structures. The films were epitaxially grown on single-crystal Fe(100) substrates. Electron diffraction measurements

Simple, Compact, High-Purity Cr Evaporator for UHV

September 1, 1993
Author(s)
Jabez J. McClelland, John Unguris, R E. Scholten, Daniel T. Pierce
A simple, compact Cr evaporator is constructed by electroplating Cr metal onto the tip of a W hairpin filament. At 5 cm from the evaporator, deposition rates up to 10 nm min -1 (flux {asymp} 10 19 atoms m -2s -1) have been obtained, with total deposition

Magnetic Moments in Cr Thin Films on Fe(100)

January 1, 1993
Author(s)
Daniel T. Pierce, Robert Celotta, John Unguris
The magnetism at the surface of a Cr film grown epitaxially on a Fe(100) whisker is observed as a function of Cr thickness by scanning electron microscopy with polarization analysis. Use of a wedge-shaped film of linearly increasing thickness allows the

Magnetism in Cr Thin Films on Fe(100)

January 1, 1992
Author(s)
John Unguris, Robert Celotta, Daniel T. Pierce
The spin polarization of secondary electrons from a Cr film on Fe(100), measured with scanning electron microscopy with polarization analysis, oscillates as a function of Cr thickness with a period near two atomic layers, consistent with incommensurate