X-ray photoelectron spectroscopy was used to analyze commercially available powders of thymine, uracil, cytosine, guanine, adenine, as well DNA isolated from salmon testes and RNA torula yeast. The were pressed onto a sample holder analyzed received the manufacturer. Survey spectra high-resolution O 1s, N C 1s all nucleobases are reported, including small Na contamination in cytosine. Spectra a...

Two different phases of the transition-metal dichalcogenide and molybdenum ditelluride (1T′-MoTe2 2H-MoTe2) were grown by chemical vapor transport. Oxygen-free surfaces generated exfoliation in air then analyzed x-ray photoelectron spectroscopy. High-resolution core valence Auger spectra acquired for both materials including Te 3d, 4d, MNN, Mo band spectra. Differences 3d peak positions that pr...

The porosity of platinum nanoparticle aggregates (PtNPs) is investigated electrochemically via particle-electrode impacts and by XPS. The mean charge per oxidative transient is measured from nanoimpacts; XPS shows the formation of PtO and PtO2 in relative amounts defined by the electrode potential and an average oxidation state is deduced as a function of potential. The number of platinum atoms...

Low-temperature (~1073 K) formation of graphene was performed on Si substrates by using an ultrathin (2 nm) Ni layer deposited on a 3C-SiC thin film heteroepitaxially grown on a Si substrate. Angle-resolved, synchrotron-radiation X-ray photoemission spectroscopy (SR-XPS) results show that the stacking order is, from the surface to the bulk, Ni carbides(Ni3C/NiCx)/graphene/Ni/Ni silicides (Ni2Si...

The in situ hydrogen-passivated Si~100!-231 surface is characterized with x-ray photoelectron spectroscopy ~XPS! and ultra-high-vacuum scanning tunneling microscopy ~STM! following exposure to ambient conditions. The XPS measurements illustrate the chemical inertness of this surface as the onset of oxidation is not observed for the first 40 h of ambient exposure. After 15 min of contact with at...

Interface properties of cobalt(II) phthalocyanine (CoPc) and cobalt(II) hexadecafluoro-phthalocyanine (CoPcF16) to gold are investigated by photo-excited electron spectroscopies (X-ray photoemission spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS) and X-ray excited Auger electron spectroscopy (XAES)). It is shown that a bidirectional charge transfer determines the interface ener...