Resolving the admixture contribution of ~2IIu and ~4Σ.- resonance states of 0~2 observed in electron scattering from multilayer thin films

摘要

We present an experimental observation of the individual ~4~-_u and ~2π_u, resonance states of 0_2 molecules seen in a multilayer solid molecular phase on graphite. The two resonances are the only allowed resonances in the energy region of 7-12.5 eV for oxygen molecules, and they are responsible for the broad peak near 9.5 eV, observed in the gas phase. A knowledge of the individual cross sections for vibrational excitation via ~4Σ~-_u: and ~2π_u resonant states in the gas phase is not yet available. Therefore, this work provides the first quantitative measurement of the two resonance states in addition to their individual contribution to the vibrational excitation peak for 0_2 near 9.5 eV.