VIBRATIONAL-SPECTRA OF KOX COMPLEXES ON GRAPHITE

KO(x) complexes on graphite, formed after potassium deposition at 160 K and different subsequent oxygen exposures, were studied by HREELS an d TDS in the temperature range 160-800 K. Annealing gives rise to a su ccession of different KO(x) complexes, partially induced by surface se gregation of intercalated potassium. A vibrational excitation at 39 me V is attributed to K2O formation. Two vibrational excitations at 30-31 and at 180 meV are probably due to KO2 or K2O2. A high temperature co mplex, which is an unidentified precursor to CO2 formation/desorption, has a single electron energy loss at 27 meV.