ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We have used ferromagnetic resonance and surface magneto-optic Kerr effect to investigate the magnetic anisotropies in face-centered-cubic fcc Cu/Co/Cu(001) structures. We have found that Cu/Co/Cu structures possess large magnetic anisotropies. The twofold perpendicular anisotropy results in a strong easy plane (4πMeff = 4πMs + Hu ∼ 40 kOe). The perpendicular uniaxial anisotropy is only weakly dependent on Co film thickness. Hu = 25.4, 23.7, and 17.7 kOe in 3- , 4- , and 10-ML-thick Co films, respectively. The twofold perpendicular anisotropy in fcc Co/Cu/Cu structures is caused by the lateral expansion and vertical contraction of fcc Co(001) ultrathin films. The in-plane fourfold anisotropy in fcc Cu/Co/Cu(001) structures has its easy axis along the [110] crystallographic direction. The fourfold in-plane anisotropy is large (2K1/Ms ∼ 1 kOe) and weakly dependent on Co film thickness. Fe(001) can be grown epitaxially on fcc Co(001) and results in a significant change in the magnetic properties. In Cu/4Co/3Fe/Cu(001) multilayer (integers describe the number of ML) the perpendicular anisotropy changes its sign and is very weak (Hu = −1.5 kOe). The in-plane fourfold anisotropy is also appreciably decreased (2K1/Ms = 0.4 kOe). Cu/4Co/6Cu/〈b〉4Co〈e〉/Cu(001) trilayers are coupled antiferromagnetically. However, this coupling is smaller (J=−0.07 ergs/cm2) compared to bcc Fe/Cu/Fe structures. The exchange coupling in Co/Cu/Co trilayers depends strongly on details of the total structure, e.g., the sample Cu/4Co/6Cu/〈b〉4Co〈e〉/3Fe/Cu is ferromagnetically coupled (J∼0.1 ergs/cm2). The exchange coupling in bcc Fe/Cu/Fe(001) trilayers oscillates with increasing Cu thickness (oscillatory period of 10 ML). However, no evidence of symmetric oscillations was found.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.348082
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