AVS 47th International Symposium
    Magnetic Interfaces and Nanostructures Friday Sessions
       Session MI-FrM

Paper MI-FrM11
Study of Exchange Anisotropy of Ni@sub 80@Fe@sub 20@/Fe@sub 60@Mn@sub 40@(111) Epitaxial Films@footnote 1@

Friday, October 6, 2000, 11:40 am, Room 206

Session: Magnetic Recording: Media and Heads
Presenter: C. Liu, University of Alabama
Authors: C. Liu, University of Alabama
G.J. Mankey, University of Alabama
Correspondent: Click to Email
Ferro-antiferromagnetic interfacial exchange anisotropy has been studied extensively.@footnote 2,3@ We have grown Ni@sub 80@Fe@sub 20@/Fe@sub 60@Mn@sub40@ fcc (111) films on epitaxial Cu(111) buffer layers on Si(110). With increasing Cu buffer layer thickness, LEED and RHEED show improving film crystal quality while atomic force microscopy reveals an increase in interfacial roughness. Films with Cu buffer layers thinner than 10 nm had coercivities less than 13 Oe, and the exchange anisotropies deduced from the hard axis initial susceptibility were consistent with the results of hysteresis loop measurements. Films with thicker Cu buffer layer had coercivities and exchange anisotropies deduced from hard axis initial susceptibility that were larger than the results of hysteresis loop measurements. For all films, the angular dependencies of exchange bias H@sub eb@ were not sinusoidal, and surprisingly, all films showed a deviation of pinned direction from the direction of the applied field during film growth. Specifically, the film with thickest Cu buffer layer (100 nm) had the largest deviation (57°). This film also exhibited the largest coercivity (47 Oe). Magnetic force microscopy measurements showed a strong ripple pattern for this film, with a length scale of 2 microns, characteristic of a strong stray field in the film. All the results revealed the inhomogeneous nature of the pinning in the films which is closely related to the canting of interfacial spins. We interpret these results based on the combination of effects of roughness and structure induced change of intrinsic magnetic properties. @FootnoteText@ @footnote 1@Funded by ARO #DAAH 04-96-1-0316 and NSF #DMR-9809423. @footnote 2@A.E. Berkowitz and Kentaro Takano, J. Magn. Magn. Mater. 200, 552(1999). @footnote 3@Joo-Von Kim, et al., Phys. Rev. B 61, 8888(2000).