[Co/Pd]-CoFeB exchange spring magnets with tunable gap of spin wave excitations
2014 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 47, no 49, 495004- p.Article in journal (Refereed) Published
Exchange spring magnets, consisting of a [Co(0.5 nm)/Pd(1 nm)](5) multilayer with perpendicular magnetic anisotropy and a Co20Fe60B20 film with easy plane anisotropy, of variable thickness t(CFB), are investigated using Brillouin light scattering. On reducing t(CFB) in the range 0.8-2.3 nm, the spin-wave frequency gap displays a remarkable increase from nearly 4-48 GHz, reflecting the corresponding rapid growth of the tilting angle of the magnetization with respect to the film normal. These findings are interpreted using a one-dimensional model in which each atomic layer is assumed to be uniformly magnetized, subjected to an effective out-of-plane or easy-plane anisotropy depending on the layer position in the stack, and exchange coupled to its two nearest neighbour atomic layers. With respect to previously investigated [Co/Pd]-NiFe hybrid magnets, a largest frequency tunability, restricted to a narrower range of the soft layer thickness, is observed.
Place, publisher, year, edition, pages
2014. Vol. 47, no 49, 495004- p.
spin waves, brillouin light scattering, exchange springs, magnetic properties of interfaces
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-158383DOI: 10.1088/0022-3727/47/49/495004ISI: 000345505100004ScopusID: 2-s2.0-84912061763OAI: oai:DiVA.org:kth-158383DiVA: diva2:779850
QC 201501132015-01-132015-01-072015-01-13Bibliographically approved