X-ray photoelectron spectroscopy (XPS) has been used to investigate the chemical structure of thin polyaniline films grown using a vacuum evaporation process that used chemically prepared polyaniline powder as the starting material. Analysis shows that the as-deposited films are in the completely reduced, leucoemeraldine state. This chemical structure is contrasted with that of the initial and residual powders, which XPS analysis shows are both in a state close to that of protoemeraldine. Thus, the results indicate that the reduction takes place either in the gas phase or, more likely, as a reaction on the surface of the substrate, but does not occur in the quartz crucible as the initial powder is being heated. Results are also presented concerning the oxidation (in pure oxygen and iodine environments) and the protonation (using HCl) of these vapor-deposited polyaniline thin films. Scanning tunneling microscopy was also used to examine the in situ growth of submonolayer coverages of polymer. Evidence for large scale structure growth, possibly resulting from crosslinking of small oligomer components, was observed.

Experimentally measured single-electron-transfer cross sections are presented for bare nuclei and one-electron ions of C, N, 0, and F following collisions with a He-gas target in the energy range from -0.5-2.5 MeU/amu. Excellent agreement is found between the K-shell ionization cross sections (electron loss by one-electron ions) and a theoretical plane-eave-Born-approximation calculation without inclusion of Coulomb-deflection and binding-energy corrections. Comparisons are also made between the capture cross sections (electron gain) and previously measured total projectile x-ray cross sections. The ratio of the x-ray cross section to the total capture cross section is compared to the same ratio found through a Brinkman-Kramers (BK) calculation. The results of the comparison show that the single normalization constant for the capture to each state, which was used in the theoretical analysis of the x-ray cross section, is inadequate. In particular, the results show that the BK calculation underestimates the capture of the electron to the 1s and 2s states as compared to the higher, x-ray-emitting states. The total capture cross sections are also given as a function of E/M (MeV/amu). For a given velocity the capture is dependent only upon the charge state of the incident ion. Also, the similar velocity dependence with average ratios of 1:0. 48:0.44 for the chargechanging processes q~-1 (q = 8, 7, and 6) correspond to a q' dependence for the total cross section.

Projectile E-Auger-electron production measurements were performed for the bare, one-, and two-electron ions of C, N, O, and F incident on He, Ne, Ar, and Kr gases. The measurements were taken over an energy range of 4 to 3 NIeV/amu using a cylindrical mirror analyzer. For the incident two-electron ions, single-electron capture to excited states of the I, '1s2s) S metastable component of the incident beam was the principal mechanism giving rise to the observed E-Auger transitions. For the bare and one-electron ions, double electron capture to excited states was the dominant mechanism leading to K-Auger-electron production. In addition to Auger-spectroscopy measurements, total E-Auger production cross sections were determined as well as the partial cross sections for electron capture to specific n levels of the projectile. The n distributions were also measured for double electron capture to excited states of the bare and one-electron ions.

Preparation of hydrogenated amorphous germanium nitrogen alloys by plasma enhanced chemical vapor deposition

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