ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We have depostied (100), (110), and (111) oriented single-crystal and polycrystalline Co1−xPtx (x=0.65, 0.75, 0.80) and polycrystalline Ni1−xPtx (x=0.25, 0.50) films over a range of growth temperatures from −50 to 800 °C. Previous work on CoPt3 films had demonstrated the correlation between Co clustering and perpendicular magnetic anisotropy.1 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 °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–Pt alloy system is similar to Co–Pt in structure, lattice constant, and the polarizability of Pt. We have deposited Ni3Pt films; these films have significant clustering of the magnetic species which drops off rapidly after the onset of bulk mobility at 400 °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 CoPt3 over three orders of magnitude at temperatures below 400 °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. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.364505
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