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High-resolution electron energy loss spectroscopy (HREELS) and X-ray photoelectron spectroscopy (XPS) have been used to investigate the adsorption of ferrocene on Ag(100) at 150 K. The HREELS data show that ferrocene adopts an orientation with the molecular axis perpendicular to the Ag(100) surface plane for low exposures. Additionally, no rehybridization is observed at the low temperature employed. Upon multilayer growth, however, the molecular axis becomes canted with respect to the surface normal. XPS for monolayer ferrocene gives Fe 2p binding energies of 707.9 and 720.8 eV for the 2p3/2 and 2p1/2 transitions, respectively, and C 1s binding energy of 284.9 eV. Monolayer surface coverage represents a molecular footprint of about one ferrocene per nine Ag surface atoms. Multilayer ferrocene grows in a layer-by-layer fashion and shows HREELS and XPS

Characteristics of decanethiol and 1,4-benzenedimethanethiol (p-BDMT) self-assembled monolayers (SAMs) grown using solution and vapor techniques were studied with X-ray photoelectron spectroscopy (XPS) and in-plane resistivity measurements. Self-assembled monolayers of decanethiol show nearly identical coverages for samples grown from solution and from vapor. Films of p-BDMT grown from solution show monolayer packing densities similar to those of alkanethiols, as indicated by the surface thiolate concentrations. A much different result is obtained for p-BDMT SAMs when grown from vapor. A monolayer packing density that is 12-16% higher than that of alkanethiols is observed with XPS and in-plane resistivity measurements. It is also shown that p-BDMT forms multilayers when SAMs are grown by both solution and vapor techniques.

Fabrication of microfluidic devices by excimer laser ablation under different atmospheres may provide variations in polymer microchannel surface characteristics. The surface chemistry and electroosmotic (EO) mobility of polymer microchannels laser ablated under different atmospheres were studied by X-ray photoelectron spectroscopy and current monitoring mobility measurements, respectively. The ablated surfaces of PMMA were very similar to the native material, regardless of ablation atmospheres due to the negligible absorption of 248-nm light by that polymer. The substrates studied that exhibit nonnegligible absorption at this energy, namely, poly(ethylene terephthalate glycol), poly(vinyl chloride), and poly(carbonate), showed significant changes in surface chemistry and EO mobility when the ablation atmospheres were varied. Ablation of these three polymer substrates under nitrogen or argon resulted in low EO mobilities with a loss of the well-defined chemical structures of the native surfaces, while ablation under oxygen yielded surfaces that retained native chemical structures and supported higher EO mobilities.