title: Bonding, backbonding, and spin-polarized molecular orbitals: basis for magnetism and semiconducting transport in V[TCNE]x approximately 2.
abstract: X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L{2,3} and C and N K edges reveal bonding and backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x approximately 2. In V spectra, d{xy}-like orbitals are modeled assuming V2+ in an octahedral ligand field, while d{z{2}} and d{x{2}-y{2}} orbitals involved in strong covalent sigma bonding cannot be modeled by atomic calculations. C and N MCD, and differences in XAS from neutral TCNE molecules, reveal spin-polarized molecular orbitals in V[TCNE]x approximately 2 associated with weaker pi bonding interactions that yield its novel properties.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Kortright
authors.forename: D M
authors.initials: DM
authors.lastname: Lincoln
authors.forename: R Shima
authors.initials: RS
authors.lastname: Edelstein
authors.forename: A J
authors.initials: AJ
authors.lastname: Epstein