Abstract: X-ray photoelectron spectroscopy at 3.5 keV photon energy, in combination with high-resolution transmission electron microscopy, is used to follow the formation of the interface between rhodium and carbon nanotubes. Rh nucleates at defect sites, whether initially present or induced by oxygen-plasma treatment. More uniform Rh cluster dispersion is observed on plasma-treated CNTs. Experimental results are compared to DFT calculations of small Rh clusters on pristine and defective graphene. While Rh interacts as strongly with the carbon as Ti, it is less sensitive to the presence of oxygen, suggesting it as a good candidate for nanotube contacts.

Abstract: The phase transformation sequences during thermal decomposition are investigated for Ni-rich melt-quenched body-centred cubic (bcc) and amorphous Ni-Zr alloys. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) are used to determine the structure of crystallization products occurring after heating the melt-spun ribbon samples to various degrees of the phase transformation process monitored by differential scanning calorimetry (DSC). A single DSC peak is observed for both the bcc and amorphous Ni(91)Zr(9) alloys and a two-step process is indicated by DSC for the amorphous Ni(90)Zr(10) alloy. In the bcc-Ni(91)Zr(9) alloy which is actually a Ni(Zr) solid solution phase, the phase transformation starts with the precipitation of Ni(5)Zr crystallites followed, after a sufficient depletion of the matrix in Zr, by the subsequent transformation of the bcc-Ni(Zr) lattice to face-centred cubic (fcc) Ni. In the amorphous alloy of the same composition, the final products are fcc-Ni and Ni(5)Zr but at intermediate stages of the phase transformation, bcc-Ni(Zr) crystallites also appear. In the a-Ni(90)Zr(10) alloy the first DSC peak corresponds to the formation of the bcc-Ni(Zr) phase which then decomposes (second DSC peak) to the equilibrium phases fcc-Ni and Ni(5)Zr. Thus, in addition to the previous observation of the formation of the metastable bcc-Ni(Zr) phase by rapid quenching from the melt, here we present evidence that this phase can form also after partial crystallization of metallic glasses of appropriate chemical compositions.

Abstract: Nanocrystalline diamond (NCD) thin films were produced by chemical vapor deposition (CVD) and doped by the addition of phosphine to the gas mixture. The characterization of the films focused on probing the incorporation and distribution of the phosphorus (P) dopants. Electron microscopy evaluated the overall film morphology and revealed the interior structure of the nanosized grains. The homogeneous films with distinct diamond grains featured a notably low sp(2):sp(3)-ratio as confirmed by Raman spectroscopy. High resolution spectroscopy methods demonstrated a homogeneous P-incorporation, both in-depth and in-plane. The P concentration in the films was determined to be in the order of 10(19) cm(-3) with a significant fraction integrated at substitutional donor sites. (C) 2014 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim

Abstract: Sr1-xLaxCuO2-delta (x=0.10-0.20) thin films exhibiting an oxygen-deficient 2 root 2a(p)x2 root a(p) x c structure (a(p) and c represent the cell parameters of the perovskite subcell) were epitaxially grown by means of pulsed laser deposition in low-pressure oxygen ambient. (001) KTaO3 and (001) SrTiO3 single crystals were used as substrates, with BaTiO3 as buffer layer. The Sr1-xLaxCuO2-delta films were oxidized during cooling down in order to yield the infinite-layer-type structure. By applying this method, high quality single-phase Sr1-xLaxCuO2 thin films could be obtained for 0.10 <= x <= 0.175 doping range. The films grown on BaTiO3/KTaO3 show superconductivity for 0.15 <= x <= 0.175 with optimum doping at x=0.15, in contrast with previously reported data. (c) 2006 American Institute of Physics.

Abstract: Nanodiamond from ozone purification (NDO) demonstrates very distinctive properties within the class of detonation nanodiamonds, namely very high acidity and high colloidal stability in a broad pH range. To understand the origin of these unusual properties of NDO, the nature of the surface functional groups formed during detonation soot oxidation by ozone needs to be revealed. In this work, thermal desorption mass spectrometry (TDMS) and IR spectroscopy were used for the identification of surface groups and it was concluded that carboxylic anhydride groups prevail on the NDO surface. On the basis of the temperature profiles of the desorbed volatile products and their mass balance, it is hypothesized that decomposition of carboxylic anhydride groups from NDO during heating proceeds by two different mechanisms. Other distinctive features of NDO in comparison with air-treated nanodiamond are also reported.

Abstract: Iron oxide nanoparticles were prepared using the simplest and most efficient chemical route, the coprecipitation, in the absence and the presence of three different and widely used surfactants. The purpose of this study is to investigate the possible influence of the different surfactants on the structure and therefore on the magnetic properties of the iron oxide nanoparticles. Thus, different techniques were employed in order to elucidate the composition and structure of the magnetic iron oxide nanoparticles. By combining transmission electron microscopy with X-ray powder diffraction and X-ray absorption fine structure measurements, we were able to determine and confirm the crystal structure of the constituent iron oxides. The magnetic properties were investigated by measuring the hysteresis loops where the surfactant influence on their collective magnetic behavior and subsequent AC magnetic hyperthermia response is apparent. The results indicate that the produced iron oxide nanoparticles may be considered as good candidates for biomedical applications in hyperthermia treatments because of their high heating capacity exhibited under an alternating magnetic field, which is sufficient to provoke damage to the cancer cells.