title: Photoinduced magnetism caused by charge-transfer excitations in tetracyanoethylene-based organic magnets.
abstract: The photoinduced magnetism in Mn-tetracyanoethylene (TCNE) molecule-based magnets is ascribed to charge-transfer excitations from manganese to TCNE. Charge-transfer energies are calculated using density functional theory; photoinduced magnetization is described using a model Hamiltonian based on a double-exchange mechanism. Photoexciting electrons from the manganese core spins into the lowest unoccupied orbital of TCNE with photon energies around 3 eV increase the magnetization through a reduction of the canting angle of the manganese core spins for an average electron density on TCNE less than one. When photoexciting with a smaller energy, divalent TCNE molecules are formed. The delocalization of the excited electron causes a local spin flip of a manganese core spin.
authors.affiliation: Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA.
authors.forename: Serkan
authors.initials: S
authors.lastname: Erdin
authors.forename: Michel
authors.initials: M
authors.lastname: van Veenendaal