Study of electronically excited states of ozone by electron-energy-loss spectroscopy

Electronically excited states of ozone have been studied by electron-energy-loss spectroscopy. Two broad bands without visible vibrational structure are observed at 1.8+/-0.2 eV and 2.05+/-0.05 eV under scattering conditions favoring singlet excitation, that is a scattering angle of theta=10 degrees and residual energy E(r)=20 eV. The lower is assigned as (1)A(2), the higher as B-1(1) (Chappuis band). Bands with rich vibrational structure are observed under scattering conditions favoring tripler excitation, theta=30 degrees-135 degrees and residual energy E(r)=1-3 eV. At least two vibrational progressions can be discerned. The first has an origin at 1.30 eV, the origin of the second cannot be determined unambiguously, it is either at 1.53 or 1.45 eV. The well-known Hartley band and a number of other singlet and triplet excited states are observed at higher energy losses. Excitation functions and angular distributions of the triplet band at 1.30 eV and of the Hartley band are presented. The absolute value of the differential cross section for excitation of the Hartley band is given. (C) 1996 American Institute of Physics.