Magnetic anisotropy and evolution of ground-state domain structures in bcc. Fe81Ni19/Co(001) superlattices
2008 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 78, no 2, 024421/1-024421/15 p.Article in journal (Refereed) Published
The magnetic anisotropy and evolution of striped magnetic domain structures in bcc. Fe81Ni19/Co(001) superlattices with the total thickness ranging from 85 to 1370 nm was studied by magneto-optical Kerr effect and magnetic force microscopy. At a thickness of âˆŒ85 nm [25 bilayers (BL)] the domains appear as stripe domains, typical for perpendicular anisotropy films, with the weak cubic anisotropy of the in-plane magnetization component stabilizing the stripe direction. The magnetic domain period strongly depends on the thickness of the superlattice. As the thickness increases, the equil. magnetization orients at oblique angles with respect to the film plane and continuously varies with the thickness from in-plane to out-of-plane. The authors 1st apply a simple phenomenol. model which correctly predicts the transition from in-plane to out-of-plane magnetization as well as increasing domain period and satn. field with increasing BL no. The results indicate partial flux-closure domains at the film surface with the tilt angle continuously varying with the superlattice thickness. By solving a linearized Landau-Lifshitz equation together with Maxwell's equations in magnetostatic approxn. for samples consisting of up to 1000 individual layers, the authors calc. the spin-wave dispersion and det. the stability conditions for the satd. ferromagnetic state. The dependence of the satn. field on the no. of layers is inferred and agrees well with the expt. The uniaxial bulk anisotropy is attributed to distortions along the c axis and the results further show evidence for the presence of an easy-plane interface anisotropy in these samples. [on SciFinder(R)]
Place, publisher, year, edition, pages
2008. Vol. 78, no 2, 024421/1-024421/15 p.
magnetic anisotropy domain structure iron nickel cobalt superlattice
IdentifiersURN: urn:nbn:se:kth:diva-78462DOI: 10.1103/PhysRevB.78.024421ISI: 000258190200080OAI: oai:DiVA.org:kth-78462DiVA: diva2:495719
CAPLUS AN 2008:936884(Journal). QC 201202202012-02-092012-02-082012-02-20Bibliographically approved