Enhanced spin-orbit coupling in tetragonally strained Fe-Co-B filmsShow others and affiliations
2017 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 29, no 27, article id 275802Article in journal (Refereed) Published
Abstract [en]
Tetragonally strained interstitial Fe-Co-B alloys were synthesized as epitaxial films grown on a 20 nm thick Au0.55Cu0.45 buffer layer. Different ratios of the perpendicular to in-plane lattice constant c/a = 1.013, 1.034 and 1.02 were stabilized by adding interstitial boron with different concentrations 0, 4, and 10 at.%, respectively. Using ferromagnetic resonance (FMR) and x-ray magnetic circular dichroism (XMCD) we found that the total orbital magnetic moment significantly increases with increasing c/a ratio, indicating that reduced crystal symmetry and interstitial B leads to a noticeable enhancement of the effect of spin-orbit coupling (SOC) in the Fe-Co-B alloys. First-principles calculations reveal that the increase in orbital magnetic moment mainly originates from B impurities in octahedral position and the reduced symmetry around B atoms. These findings offer the possibility to enhance SOC phenomena - namely the magnetocrystalline anisotropy and the orbital moment - by stabilizing anisotropic strain by doping 4 at.% B. Results on the influence of B doping on the Fe-Co film microstructure, their coercive field and magnetic relaxation are also presented.
Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2017. Vol. 29, no 27, article id 275802
Keywords [en]
Fe-Co-B, ferromagnetic resonance, g-factor, magnetic anisotropy, orbit coupling, spin, tetragonal strain, x-ray magnetic circular dichroism, Binary alloys, Calculations, Copper alloys, Crystal impurities, Crystal symmetry, Dichroism, Epitaxial growth, Ferromagnetic materials, Ferromagnetism, Gold alloys, Iron alloys, Magnetic moments, Magnetic storage, Magnetocrystalline anisotropy, Semiconductor doping, Spectroscopy, X rays, G factors, Cobalt alloys
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:oru:diva-83930DOI: 10.1088/1361-648X/aa7498ISI: 000403326600001Scopus ID: 2-s2.0-85020500919OAI: oai:DiVA.org:oru-83930DiVA, id: diva2:1449114
2020-06-292020-06-292020-06-29Bibliographically approved