Effect of transition-metal overlayers on the perpendicular magnetism of MBE-grown, ultra-thin Co films

Journal Article · Sat May 15 04:00:00 EDT 1993 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.352694· OSTI ID:6678861

Engel, B N; Wiedmann, M H; Van Leeuwen, R A; Falco, C M ^[1]

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1. Physics Department and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721 (United States)

We have used [ital in] [ital situ] polar Kerr ellipticity measurements to study the perpendicular magnetic behavior of MBE-grown Pd/Co/TM sandwich structures, where TM is the nonmagnetic transition metal overlayer Pd, Cu, or Ag. These structures are epitaxially deposited on thick Pd (111) buffer layers grown on Co-seeded GaAs (110) substrates. Hysteresis curves were measured [ital in] [ital situ] for systematically varied Co and TM layer thicknesses 2 A[le][ital t][sub Co][le]10 A and 0 A[le][ital t][sub TM][le]200 A. We observed perpendicular loops with a coercive field of [ital H][sub [ital c]][le]200 Oe for the uncovered Co films for [ital t][sub Co][le]6 A, becoming in-plane above this thickness. However, subsequent deposition of just one atomic layer ([approx]2 A) of any of the TM over the Co resulted in strongly perpendicular, square hysteresis curves with [ital H][sub [ital c]][ge]700 Oe for all films in the Co thickness range studied. Deposition of TM overlayers causes nonmonotonic behavior in [ital H][sub [ital c]] as a function of coverage. We find a peak in [ital H][sub [ital c]] at a TM coverage of [ital t][sub TM][similar to]1.5 A for all materials, with a subsequent monotonic increase above [ital t][sub TM][approx]4 A to a limiting value by [ital t][sub TM][approx]100 A. The peak is most pronounced for Cu, where [ital H][sub [ital c]] changes by more than 200%.

• DOE Contract Number: FG02-87ER45297
• OSTI ID: 6678861
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 73:10; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
COBALT
COPPER
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
ELEMENTS
EPITAXY
FILMS
KERR EFFECT
LAYERS
MAGNETIC PROPERTIES
METALS
MOLECULAR BEAM EPITAXY
PALLADIUM
PHYSICAL PROPERTIES
PLATINUM METALS
SILVER
THIN FILMS
TRANSITION ELEMENTS