The kinetic and internal energies of OH(A²Σ⁺) produced by electron stimulated desorption from TiO₂, NaCl and SrF₂ surfaces

Abstract

The kinetic and internal energies of OH(A 2Σ+) radicals produced by electron-stimulated desorption from H2O-exposed TiO2, NaCl and SrF2 surfaces are reported. The kinetic energies were determined by measuring the spatial extent of the fluorescence above each substrate surface, while the vibrational and rotational energies were determined by analyzing the intensity distribution of the rovibrational spectra. We find that OH* from NaCl and SrF2 has low kinetic energy, 80 and 150 meV, respectively, and low rotational excitation, Trot ≈ 340-450 K. OH* from TiO2 is more energetic, Ekin = 250 meV and Trot ≈ 1000 K. The OH* vibrational excitation is high. Tvib ≈ 2000 K, and independent of the nature of the substrate. © 1986.