Layers of BC x N y were produced in a chemical vapour deposition (CVD) process using trimethylamine borane with He, N 2 , and NH 3 , respectively, as precursor. These layers deposited on Si (100) wafers were characterized chemically by X-ray photoelectron spectroscopy (XPS) and synchrotron radiation-based total reflection X-ray fluorescence analysis combined with near-edge X-ray absorption fine structure spectroscopy (TXRF-NEXAFS). As a result, the composition of the material produced without NH 3 is a B-C bonds containing compound with an atomic relation 1 : 1. Adding NH 3 with a partial pressure of up to about 1.3 Pa the product could be identified as B 2 C 2 N. Increasing the partial pressure of NH 3 to 1.7 and 2.1 Pa the product was enriched in nitrogen yielding a compound characterized as h-BCN. In all cases an impurity of oxygen was observed.

Triethylamine borane (TEAB) and He, N(2) or NH(3) were applied as additional reaction gases in the production of BC(x)N(y) layers by low-pressure chemical vapor deposition (LPCVD). These layers were deposited on Si(100) wafers and characterized chemically by X-ray photoelectron spectroscopy (XPS) and synchrotron radiation-based total-reflection X-ray fluorescence analysis combined with near-edge X-ray absorption fine-structure spectroscopy (TXRF-NEXAFS). The composition of the material produced without NH(3) was found to be dominated by B-C bonds with the stoichiometric formula B(2)C(3)N. B-N bonds with the formula B(2)CN(3) were preferred when NH(3) was added. A first attempt was made to compare the results obtained by applying trimethylamine borane and TEAB as single-source precursors.

Improvement in the performance of functional nanoscaled devices involves novel materials, more complex structures, and advanced technological processes. The transitions to heavier elements and to thicker layers restrict access to the chemical and physical characterization of the internal material interfaces. Conventional nondestructive characterization techniques such as X-ray photoelectron spectroscopy suffer from sensitivity and quantification restrictions whereas destructive techniques such as ion mass spectrometry may modify the chemical properties of internal interfaces. Thus, novel methods providing sufficient sensitivity, reliable quantification, and high information depths to reveal interfacial parameters are needed for R&D challenges on the nanoscale. Measurement strategies adapted to nanoscaled samples enable the combination of Near-Edge X-ray Absorption Fine Structure and Grazing Incidence X-ray Fluorescence to allow for chemical nanometrology of internal material interfaces. Their validation has been performed at nanolayered model structures consisting of a silicon substrate, a physically vapor deposited Ni metal layer, and, on top, a chemically vapor deposited B(x)C(y)N(z) light element layer.

Films of BC(x)N(y) were produced in a plasma-enhanced chemical vapor deposition process using trimethylborazine as precursor and with H2, He, N2, and NH3, respectively, as auxiliary gas. These films deposited on Si(100) wafers or fused quartz glass substrates were characterized chemically by X-ray photoelectron spectroscopy and by synchrotron radiation-based total-reflection X-ray fluorescence combined with near-edge X-ray absorption fine structure. Independent of the auxiliary gas, the B-N bonds are dominating. Furthermore, B-C and N-C bonds were identified. Oxygen, present in the bulk (in contrast to the surface layer of some nanometers, where molecular oxygen and/or water are absorbed) as an impurity, is bonded to boron or to carbon, respectively. The relation of boron and nitrogen changes with the character of the auxiliary gas: cB/cN approximately = 4:3 (for H2 and He) and cB/cN approximately = 1 (for N2 or NH3). Furthermore, physical properties such as the refractive index and the optical band-gap energy were determined.

CoMo catalysts supported on meso/macroporous alumina have been designed for hydrotreating of heavy oil. Pellets were prepared from pseudoboehmite and polystyrene colloidal crystals with subsequent CoMo compounds supporting on alumina. Supports, fresh and spent catalysts were characterized by crushing tests, X-ray diffraction, scanning and high-resolution transmission electron microscopies, N 2 sorption and pycnometric techniques, mercury porosimetry, and different methods of elemental analyses. The hydrotreating experiments were carried out at 380−420 °C and 70 bar in the presence of CoMo catalysts supported on meso/macroporous or reference mesoporous alumina. Viscosity, desulfurization extent, microcarbon residue, and asphaltenes content were determined for the reaction products. CoMo compounds supported on meso/macroporous Al 2 O 3 had transformed to the layered sulfides under the influence of reaction medium, while no significant changes of supported compounds were observed for the reference mesoporous catalyst. The bimodal meso/macroporous catalyst had increased activity in hydrodemetallization and hydrodesulfurization reactions compared with the mesoporous analogue.

Mountain lakes in East Siberia have been studied for recent changes in water chemistry, turbidity and diatom assemblages preserved in bottom sediments. We performed a regional analysis of the relative effect of climate and glacier changes on change in diatom diversity and supply of meltware in proglacial lakes. We analysed sediment records from East Siberian glacier lakes using geochemical and diatoms proxies. We found that dramatic changes in communities and abundance of diatoms and biogenic proxy could be induced by low nutrient concentrations in glacial lakes and high turbidity due to active degradation of glaciers and snow patches as a result of the global increase in temperature in the Northern Hemisphere. Our evidences show that diatoms have been gradually decreased since ca. the 1880s. A significant tendency towards diatom reducing occurred at high summer regional temperatures. This tendency may be attributed to the fact that glaciers and snow patches thawed actively in East Siberia during ca. 1880-1958, which was induced by the beginning of the Recent Warming (ca. 1850-1860) and a long period of relatively warm regional climate from ca. 1900 to 1960.

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BCxNy films were produced from single‐source precursors in a chemical vapor deposition process. The boranes were introduced as precursors at low pressure conditions and at a temperature of 700 °C, whereas the borazine was handled at 400 °C and with a plasma enhancement at an electrical power input of 40 W. Additionally, as inert or reactive gases, H2, He, N2, and NH3, respectively, were used. The films deposited on Si(100) substrates were chemically characterized by X‐ray photoelectron spectroscopy and by synchrotron radiation‐based total‐reflection X‐ray fluorescence combined with near‐edge X‐ray absorption fine structure and quantified elementally by energy‐dispersive X‐ray spectroscopy. The results are critically compared. With the application of boranes without NH3, compounds with a dominating carbidic character were identified, whereas with the addition of NH3 to the boranes, a nitridic character was prevalent. In case of using borazine for the synthesis, the nitridic character was found at the application of all auxiliary gases. For both groups stoichiometric formulas derived from energy‐dispersive X‐ray spectroscopy are proposed: B3.5–4C4N2–2.5 for the carbidic region and B3.5C1.5N5 for the nitridic region. Copyright © 2012 John Wiley & Sons, Ltd.