Surface-induced clustering in vapor deposited Co{sub 1{minus}x}Pt{sub x} and Ni{sub 1{minus}x}Pt{sub x} films (abstract)

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.364505· OSTI ID:554270

Shapiro, A L; Rooney, P W; Tran, M Q; Hellman, F ^[1]

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1. Department of Physics, University of California--San Diego, La Jolla, California 92093-0350 (United States)

We have depostied (100), (110), and (111) oriented single-crystal and polycrystalline Co{sub 1{minus}x}Pt{sub x} (x=0.65, 0.75, 0.80) and polycrystalline Ni{sub 1{minus}x}Pt{sub x} (x=0.25, 0.50) films over a range of growth temperatures from {minus}50 to 800{degree}C. Previous work on CoPt{sub 3} films had demonstrated the correlation between Co clustering and perpendicular magnetic anisotropy. These observations motivated a model in which Co atoms cluster on the growing surface; this clustering is trapped by succeeding layers for growth temperatures below 400{degree}C, the lower limit of bulk atomic mobility. The (110) oriented samples show clustering and anisotropy identical to the (100) and (11) oriented samples despite the sign change of the surface segregation in the (110) orientation. The Ni{endash}Pt alloy system is similar to Co{endash}Pt in structure, lattice constant, and the polarizability of Pt. We have deposited Ni{sub 3}Pt films; these films have significant clustering of the magnetic species which drops off rapidly after the onset of bulk mobility at 400{degree}C. No perpendicular magnetic anisotropy is found in these films, even though interface magnetic anisotropy values in Ni/Pt multilayers have been reported as having up to 1/4 the value of Co/Pt interfaces. Finally, in order to explore whether surface clustering is a kinetic or equilibrium effect, we have varied the deposition rate of CoPt{sub 3} over three orders of magnitude at temperatures below 400{degree}C. We found no dependence of clustering or anisotropy on the deposition rate, suggesting that the clustering is not kinetically limited but is a surface equilibrium effect. {copyright} {ital 1997 American Institute of Physics.}

• DOE Contract Number: FG03-95ER45529
• OSTI ID: 554270
• Report Number(s): CONF-961141--
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ATOMIC CLUSTERS
COBALT ALLOYS
DEPOSITION
LAYERS
MAGNETIZATION
NICKEL ALLOYS
PLATINUM ALLOYS
THIN FILMS