uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Magnetic coupling of Fe-porphyrin molecules adsorbed on clean and c(2 x 2) oxygen-reconstructed Co(100) investigated by spin-polarized photoemission spectroscopy
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Show others and affiliations
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 18, 184411- p.Article in journal (Refereed) Published
Abstract [en]

The spin-polarized electronic structure of iron octaethylporphyrin (FeOEP) molecules adsorbed on a pristine and on a c(2 x 2) oxygen-reconstructed Co(100) surface has been analyzed by means of spin-polarized photoemission spectroscopy (SPPES) and first-principles density functional theory with the on-site Coulomb repulsion U term (DFT + U) calculations with and without Van der Waals corrections. The aim is to examine the magnetic exchange mechanism between the FeOEP molecules and the Co(100) substrate in the presence or absence of the oxygen mediator. The results demonstrate that the magnetic coupling from the ferromagnetic substrate to the adsorbed FeOEP molecules is ferromagnetic, whereas, the coupling is antiferromagnetic for the FeOEP on the c(2 x 2)O/Co(100) system. Spin-resolved partial densities of states extracted from ab initio DFT + U modeling are in fairly good comparison with the electronic spectral densities seen in angle-integrated SPPES energy dispersion curves for submonolayer coverages of FeOEP. Through combined analysis of these spectra and theoretical results, we determine that hybridization of 2p orbitals of N and O with Co 3d orbitals facilitates indirect magnetic exchange interactions between Fe and Co, whereas, a direct Fe-Co interaction involving the Fe d(z)2 orbital is also found for FeOEP on Co. It is observed through SPPES that the spin polarization of the photoemission-visible molecular overlayers decreases to zero as coverage is increased beyond the submonolayer regime, indicating that only interfacial magnetic coupling is at work. Microspot low-energy electron diffraction and low-energy electronmicroscopy were performed to characterize the physical order of the molecular coverage, revealing that FeOEP structural domains are orders of magnitude greater in size on c(2 x 2)O/Co(100) than on clean Co(100), which coincides with reduced scattering from the disorder and sharper features seen in SPPES.

Place, publisher, year, edition, pages
2013. Vol. 87, no 18, 184411- p.
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-202371DOI: 10.1103/PhysRevB.87.184411ISI: 000318809800004OAI: oai:DiVA.org:uu-202371DiVA: diva2:631918
Available from: 2013-06-24 Created: 2013-06-24 Last updated: 2013-06-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Ali, Md EhesanTarafder, KartickOppeneer, Peter M.
By organisation
Materials Theory
In the same journal
Physical Review B. Condensed Matter and Materials Physics
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 161 hits
ReferencesLink to record
Permanent link

Direct link