Dissociative electron attachment to N2O clusters:: attachment spectra for (N2O)nO- anions (n=0-7) from about 0 up to 25 eV

Using a recently constructed high resolution crossed beams apparatus involving a hemispherical electron monochromator we have studied from threshold up to 25 eV electron attachment to N2O clusters in the size range up to about 10, Attachment spectra obtained for the production of (N2O)(n)O- exhibit with increasing cluster size a gradual redshift of the maximum peak position of the major rather broad resonance located at around 2 eV, i.e. values varying from 2.58 +/- 0.1 eV for O- to 1.70 +/- 0.1 eV for (N2O)(7)O-. In addition, with increasing cluster size the anion signal is more fully developed near 0 eV, i.e., whereas for n = 0 the O- ion signal is zero at about zero energy (in accordance with expectations from thermochemical data), there exists an appreciable ion signal at zero energy for n = 7. Above the 2 eV resonance there exists a shallow minimum in the cross section at about 4 eV with a slightly increasing, probably structured, broad feature toward higher energies. The present results are compared to previous attachment studies concerning the monomer and clusters of N2O and to O- desorption studies from condensed N2O thereby elucidating the origin and evolution (under different phase conditions) of the various features of the attachment spectra. (C) 2001 Elsevier Science B.V.