Coulomb interactions in rubidium-doped tetracyanoethylene: a model system for organometallic magnets
2004 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 69, no 16, 165208- p.Article in journal (Refereed) Published
The electronic structure of tetracyanoethylene (TCNE) has been studied both in its pristine state and upon stepwise rubidium intercalation, by UV and x-ray photoelectron spectroscopy as well as with theoretical calculations. The intercalated system may serve as a model for TCNE-based organometallic magnets, of which the electronic structure remains largely unknown. Rubidium is found to n-dope the TCNE molecules forming Rb+TCNE- with almost complete charge transfer. Calculations show a spin splitting of the former highest occupied molecular orbital level upon Rb doping. We see no evidence for the formation of doubly charged TCNE molecules. A gap opens up at the Fermi energy for Rb+TCNE- due to on-site Coulomb interactions. We estimate the on-site Coulomb interaction of amorphous TCNE doped with Rb to be ∼2 eV.
Place, publisher, year, edition, pages
2004. Vol. 69, no 16, 165208- p.
IdentifiersURN: urn:nbn:se:liu:diva-13871DOI: 10.1103/PhysRevB.69.165208OAI: oai:DiVA.org:liu-13871DiVA: diva2:22056