Increased magnetocrystalline anisotropy in epitaxial Fe-Co-C thin films with spontaneous strain
2014 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 116, no 21, 213901- p.Article in journal (Other academic) Published
Rare earth free alloys are in focus of permanent magnet research since the accessibility of the elements needed for nowadays conventional magnets is limited. Tetragonally strained iron-cobalt (Fe-Co) has attracted large interest as promising candidate due to theoretical calculations. In experiments, however, the applied strain quickly relaxes with increasing film thickness and hampers stabilization of a strong magnetocrys- talline anisotropy. In our study we show that already 2 at% of carbon substantially reduce the lattice relaxation leading to the formation of a spontaneously strained phase with 3% tetragonal distortion. In these strained (Fe0.4Co0.6)0.98C0.02 films, a magnetocrystalline anisotropy above 0.4 MJ/m3 is observed while the large polarization of 2.1 T is maintained. Compared to binary Fe-Co this is a remarkable improve- ment of the intrinsic magnetic properties. In this paper, we relate our experimental work to theoretical studies of strained Fe-Co-C and find a very good agreement.
Place, publisher, year, edition, pages
2014. Vol. 116, no 21, 213901- p.
Fe-Co, rare earth free permanent magnet, magnetocrystalline anisotropy, tetragonal strain, DFT, RHEED
Condensed Matter Physics
Research subject Physics with spec. in Atomic, Molecular and Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-231846DOI: 10.1063/1.4901595ISI: 000346007400017OAI: oai:DiVA.org:uu-231846DiVA: diva2:745322
FunderEU, European Research Council