The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified. Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.
A series of n-cycloparaphenylenes ([n]CPP) were studied by ultraviolet photoemission, inverse photoemission, ultraviolet-visible absorption, and X-ray photoemission spectroscopy to detect their unique electronic structures. [n]CPP has a cyclic structure in...
We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.
The metallic and semiconducting character of a large family of organic materials based on the electron donor molecule tetrathiafulvalene (TTF) is rooted in the partial oxidation (charge transfer or mixed valency) of TTF derivatives leading to partially filled molecular orbital-based electronic bands. The intrinsic structure of such complexes, with segregated donor and acceptor molecular chains or planes, leads to anisotropic electronic properties (quasi one-dimensional or two-dimensional) and morphology (needle-like or platelet-like crystals). Recently, such materials have been synthesized as nanoparticles by intentionally frustrating the intrinsic anisotropic growth. X-ray photoemission spectroscopy (XPS) has emerged as a valuable technique to characterize the transfer of charge due to its ability to discriminate the different chemical environments or electronic configurations manifested by chemical shifts of core level lines in high-resolution spectra. Since the photoemission process is inherently fast (well below the femtosecond time scale), dynamic processes can be efficiently explored. We determine here the fingerprint of partial oxidation on the photoemission lines of nanoparticles of selected TTF-based conductors.
Yb \(L_{3}\) Resonant Hard X-Ray Photoemission Spectroscopy of Valence Transition Compound YbInCu4