Electronic properties of potassium doped FePc from electron energy-loss spectroscopy.

We have studied the electronic structure of potassium doped iron phthalocyanine (FePc) phases using electron energy-loss spectroscopy. The electronic excitation spectrum of FePc is rather complex and comprises both pi-pi( *) transitions of the phthalocyanine ligand and transitions that involve the Fe 3d orbitals. This allows deeper insight into the orbital occupation in FePc. Potassium doping, i.e., the addition of electrons to the FePc molecules causes significant changes in the electronic excitations, which signal filling of pi( *) as well as Fe 3d orbitals.