Volume 21, Issue 1, December 2014
Index of content:
21(2014); http://dx.doi.org/10.1116/11.20140101View Description Hide Description
β-Fe2O3-CuO nanosystems were developed by using a two-step vapor-phase strategy. β-Fe2O3 matrices (hosts) were initially deposited by Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) on Indium Tin Oxide (ITO) substrates. Subsequently, CuO nanoparticles (NPs, guests) were over-deposited by means of Radio Frequency (RF)-sputtering under mild preparation conditions. A thorough characterization highlighted the dispersion of CuO NPs inside the host iron oxide. To this regard, X-ray Photoelectron and X-ray Excited Auger Electron Spectroscopies (XPS and XE-AES) analyses provided valuable information on the system chemical composition. In particular, attention has been devoted to the analysis of the O 1s, Fe 2p, Cu 2p core levels and Cu LMM Auger peak, employing a non-monochromated MgKα source. The investigation confirmed the presence of Fe(III) and Cu(II) oxides, highlighting the formation of nanocomposites in which the host and guest species maintained their chemical identity.
21(2014); http://dx.doi.org/10.1116/11.20130902View Description Hide Description
In this investigation, thermal vapor deposition was used to synthesize films of polyvinylidene fluoride (PVDF) containing nanoparticles of the ceramic titanium dioxide (TiO2). This ferroelectric polymer has shown promise as a capacitor dielectric material with possible enhanced electrical properties when combined with ceramic nanoparticles. The films were synthesized starting from a mixture of PVDF and TiO2 (rutile phase) dissolved in dimethylformamide (DMF) solvent. The PVDF-TiO2 mixture was vapor deposited onto a Si wafer. The temperature during the deposition was approximately 400 °C and the deposition time was 15 min. The deposited films were characterized using x-ray photoelectron spectroscopy (XPS). It is noted that various starting mixtures and deposition parameters were investigated. The spectra reported here are from films from two different initial PVDF/TiO2 mixtures (prior to deposition). For the maximum concentration of TiO2 in the deposited films, the Ti atomic concentration is just under 10%. Analysis from XPS shows a defluorination of the films (C/F ratio >1) from the deposition process, with the final film being a mixture of PVDF and polyvinyl fluoride (PVF). It is also noted that energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM) show that the TiO2 nanoparticles are homogeneously distributed in the films. The reported XPS spectra include survey and high resolution scans of the major photoelectron peaks.
21(2014); http://dx.doi.org/10.1116/11.20140401View Description Hide Description
Molybdenum disulfide (MoS2), a two-dimensional material purchased from SPI supplies, was analyzed using high-resolution X-ray photoelectron spectroscopy (XPS). A flake was mechanically exfoliated from a MoS2 bulk single crystal for the study. The XPS spectra of MoS2 obtained using monochromatic Al K α radiation at 0.83401 nm include a survey scan, high-resolution spectra of O 1s, Mo 3p, C 1s, Mo 3d, S 2s, S 2p, Mo 4s, Mo 4p, S 3s, and valance band. Extended energy ranges were collected in the vicinity of the Mo 3d/S 2s, S 2p, and Mo 4s/Mo 4p/S 3s/Valence band regions allowing for fitting of surface plasmon features and determination of Tougaard scattering cross-section parameters. Quantitative analysis indicates a surface composition of MoS1.9.
21(2014); http://dx.doi.org/10.1116/11.20140301View Description Hide Description
We report the characterization of a thin film of propylene carbonate acquired at −120 °C deposited onto an aluminum substrate using a cold stage. Reference spectra for propylene carbonate were acquired using monochromatic Al K α radiation. An XPS survey scan, a C 1s narrow scan, an O 1s narrow scan, an O KLL Auger narrow scan, an O 2s narrow scan and a valence band narrow scan were collected.