Paper MI-ThP4
Core and Valence Band Photoemission of M[TCNE] Organic-based Magnets

Thursday, November 12, 2009, 6:00 pm, Room Hall 3

A family of organic-based magnets of M^II[TCNE]_x•zS (M = V, Mn, Fe, Co, Ni; TCNE = tetracyanoethylene; S = CH₂Cl₂) composition exhibit ordering temperatures ranging from 44 (M = Co, Ni) to ~400 K for M = V. The exchange mechanism in this class of magnets is not well understood and changes dramatically with transition metal type. Core and valence band photoemission have been completed, above and below the transition temperature for the above systems and will be presented. The binding energies of the metal and organic core levels, relative to M^II and [TCNE]^•- will be presented within the context of exchange strength, transition temperature and metal-to-ligand symmetry overlap. The goal of our groups is to provide, through multiple spectroscopies (some pressure dependent), a picture for the binding energy and spin polarization of the occupied/unoccupied electronic structure as well as the exchange mechanism and bonding as the transition metal type is varied in roughly the same physical structure.