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The mechanism of graphitic ordering of atomic C on Ni was investigated at temperatures ranging from room temperature to 550 °C. The C/Ni films were prepared by ion beam sputtering. Their structure has been determined by Rutherford backscattering spectrometry/nuclear reaction analysis, X-ray photoelectron spectroscopy, Raman spectroscopy and cross-sectional transmission electron microscopy. A temperature-induced and a Ni-induced enhancement of graphitic ordering is demonstrated. The Ni-effect is responsible for the formation of a bi-layer structure of the C films at higher deposition temperatures. In the bi-layers, C forms graphenic planes parallel to the Ni surface within a thickness range of 1–2 nm. Further deposited C grows preferentially perpendicular to the surface. The results are discussed on the basis of hyperthermal atom deposition, surface diffusion, metal-induced crystallization and dissolution-precipitation. Our findings point to a dominating role of surface diffusion-assisted crystallization in the carbon ordering process. [ABSTRACT FROM AUTHOR]

Highlights: [•] LaLuO3 and LaScO3 layers were treated by flash lamp annealing. [•] FLA does not affect the very low leakage currents or the k-values of and LaScO3. [•] TiN oxidation in a gate-first processing scheme can be prevented by a Si-cap on TiN. [•] MOS capacitors are evaluated for oxide charges. [Copyright &y& Elsevier]

The influence of N content on the crystallization behavior of initially amorphous Ta–Si–N diffusion barriers deposited with a thickness of 10 nm between Cu and SiO2 was investigated by means of glancing angle X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GD-OES), transmission electron microscopy (TEM), and graphite furnace atomic absorption spectrometry (GF-AAS) after annealing for various times at a temperature of Tan=600 °C. For a Ta73Si27 film, only Ta silicide phases (Ta5Si3, Ta2Si) are formed, whereas all barriers containing nitrogen crystallize primarily into a Ta nitride. Si is not incorporated into this phase but diffuses mostly into the Cu film. Although the crystalline Ta nitride grows mainly within the original barrier region, it does not form a continuous layer. For barriers with a N content xN≥25 at.%, the annealing time necessary to start the crystallization increases and the formed Ta nitride phases become N-richer (Ta2N→Ta5N6). A Ta30Si18N52 layer maintains its amorphous structure even after annealing for tan=100 h. With increasing N content in the barrier, the thermal stability against Cu diffusion is improved. [Copyright &y& Elsevier]

The degradation mechanisms of 10 nm thick Ta and Ta73Si27 diffusion barriers deposited between Cu and SiO2 are compared by means of X-ray reflectometry, glancing angle X-ray diffraction, glow discharge optical emission spectroscopy depth profiling and transmission electron microscopy analysis. Annealing the samples at Tan=600 °C for tan=1 h results in a diffusion of Ta atoms through the Cu capping layer to the sample surface, particularly in the case of the pure Ta barrier. During longer heat treatment (tan>1 h), microstructural changes occur within both barrier types. Whereas the amorphous Ta–Si layer starts to crystallize into Ta5Si3, the initially grown metastable β-Ta of the pure Ta film transforms into the equilibrium α-Ta phase. Analyzing the diffusion rate of Cu atoms into the substrate, the Ta73Si27 barrier shows an enhanced thermal stability compared to the pure Ta film. [Copyright &y& Elsevier]

Abstract: Titanium aluminium nitride (TiAlN) coatings have been grown by reactive (Ar/N2) direct-current magnetron sputtering from a Ti50Al50 compound target. The film composition has been quantified by ion beam analysis showing the formation of Al-rich nitrides (Ti/Al∼0.3), with stoichiometric films for N2 contents in the gas mixture equal or above ∼25%. The surface morphology of the films has been imaged by atomic force microscopy, showing very smooth surfaces with roughness values below 2nm. X-ray and electron diffraction patterns reveal that the films are nanocrystalline with a wurzite (w) structure of lattice parameters larger (∼2.5%) than those for w-AlN. The lattice expansion correlates with the Ti/Al ratio in stoichiometric films, which suggests the incorporation of Ti into w-AlN. The atomic environments around Ti, Al and N sites have been extracted from the X-ray absorption near-edge structure (XANES) by recording the Ti2p, Al1s and N1s edges, respectively. The analysis of the XANES spectral lineshape and comparison with reported theoretical calculations confirm the formation of a ternary hexagonal phase. [Copyright &y& Elsevier]

Abstract: Settling velocity tubes (SVTs), as originally proposed by Owen (1976), remain important instruments to determine in-situ sediment settling velocity distributions, particularly in estuaries. Because there is still a need for SVTs in the field, this note provides the theoretical basis for the analysis of the samples taken from SVTs; together with a MATLAB script to execute this analysis and detailed documentation on its use. The script, which is based on Jones and Jago''s (1996) original procedure, includes two additional constraints on the slopes of the curve fitted to the percentage of sediment in suspension with time, which help to control the fit. [Copyright &y& Elsevier]

Abstract Room temperature implantation of 30 keV Co ions into an amorphous carbon film with a high fluence of 1.2 × 1017 Co/cm2 results in formation of magnetic nanostructures displaying multiple magnetic phases. Cross-sectional TEM images show formation of Co containing nanoparticles at the surface and near-surface regions of the implanted films. EDXS measurements suggest the nanoparticles to be composed primarily of Co and O at the surface and Co and C in deeper regions. These nanoparticles with differing compositions were observed to be segregated by a thin layer devoid of Co. Magnetic measurements reveal the presence of superparamagnetic behavior from small Co x C nanoclusters with a blocking temperature of 5 K. There is a small fraction of larger Co x C nanoclusters that show magnetic hysteresis even at room temperature. The saturation magnetic moment is as high as 0.51 μ B /Co at 2 K and 0.32 μ B /Co at room temperature. Spin-disorder is seen with a range of spin glass temperatures below ∼70 K. Our high fluence Co implantation into amorphous carbon has resulted in the formation of complex magnetic nanostructures composed of cobalt, oxygen, and carbon. These nanostructures give rise to multiple magnetic phases such as superparamagnetism, spin glass, ferromagnetism, and possibly antiferromagnetism. Graphical abstract Image 1 Highlights • Multiple magnetic phases and complex nanostructured material from high fluence Co implantation into a-C. • Superparamagnetic behavior from nanoclusters with a blocking temperature of 5 K. • Spin glass behavior is seen at temperatures below ∼70 K. • Small fraction of larger nanoclusters that show hysteresis even at room temperature. • Saturation magnetic moment of 0.51 μ B /Co at 2 K and 0.32 μ B /Co at room temperature. [ABSTRACT FROM AUTHOR]

This study combines the interaction between the toxic oxyanions selenite and selenate and the plant growth promoting bacterium Azospirillum brasilense with a comprehensive characterization of the formed selenium particles. As selenium is an essential trace element, but also toxic in high concentrations, its state of occurrence in nature is of major concern. Growth of the bacterium was affected by selenite (1–5 mM) only, observable as a prolonged growth lag-phase of 3 days. Subsequently, selenite reduction occurred under aerobic conditions resulting in extracellularly formed insoluble Se 0 particles. Complementary studies by microscopic and spectroscopic techniques revealed the particles to be homogeneous and stable Se 8-n S n structured spheres with an average size of 400 nm and highly negative surface charge of −18 mV in the neutral pH range. As this is the first study showing Azospirillum brasilense being able to biotransform selenite to selenium particles containing a certain amount of sulfur, even if environmental waters supplemented with selenite were used, they may significantly contribute to the biogeochemical cycling of both elements in soil as well as to their soil-plant transfer. Therefore, microbial biotransformation of selenite under certain circumstances may be used for various bio-remediation and bio-technological applications. [ABSTRACT FROM AUTHOR]

We investigate the correlation between roughness, remanence and coercivity in Co/Ni films grown on Cu seed layers of varying thickness. Increasing the Cu seed layer thickness of Ta/Cu/8×[Co/Ni] thin films increases the roughness of the films. In-plane magnetization loops show that both the remanence and coercivity increase with increasing seed layer roughness. Polar Kerr microscopy and magnetic force microscopy reveal that the domain density also increases with roughness. Finite element micromagnetic simulations performed on structures with periodically modulated surfaces provide further insight. They confirm the connection between domain density and roughness, and identify the microsocpic structure of the domain walls as the source of the increased remanence in rough films. The simulations predict that the character of the domain walls changes from Bloch-like in smooth films to Néel-like for rougher films. [ABSTRACT FROM AUTHOR]

Focused ion irradiation of insulating diamond-like carbon (DLC) films is a well-recognized approach to write defined nanostructures with drastically changed properties compared to the unexposed matrix. In particular, the electrical conductivity of the film areas that are irradiated increases by several orders of magnitude. Furthermore it is known that the conductivity increase is directly related to the irradiation-induced sp 3 –sp 2 rehybridization. This experimental work shows in detail that ion-induced microstructural ordering of the carbon atom arrangement far beyond the sp 3 –sp 2 conversion saturation is an important microscopic mechanism for the alteration of physical properties, including an increase in the conductivity. The atomic ordering correlates with the local energy density deposited during the ion impact. Thus the ion-induced phase transformation of DLC is proposed to comprise a rehybridization stage, caused by nuclear collisions, and a rearrangement stage (graphite-like ordering) that is thermally driven by the ion impact. These conclusions are based on in-depth investigations of amorphous DLC films that were locally irradiated by a number of ion species employing several temperature regimes. The ion irradiation experiments cover a wide range of fluences. X-ray photoelectron spectroscopy, μ-Raman spectroscopy, transmission electron microscopy, and low temperature transport measurements have been applied to characterize the films. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal supply pathway determines the Ion Beam Sputtering surface pattern properties. • Fe+ beam irradiation produces a surface pattern with short-range hexagonal ordering. • Compositional and morphological pattern correlation depends on the metal pathway. • The Fe+ pattern dynamics shares features with both the Xe+ and Fe co-deposited cases. The dynamics of the pattern induced on a silicon surface by oblique incidence of a 40 keV Fe ion beam is studied. The results are compared with those obtained for two reference systems, namely a noble gas ion beam either without or with Fe co-deposition. The techniques employed include Atomic Force Microscopy, Rutherford Backscattering Spectrometry, Transmission Electron Microscopy, X-ray Photoelectron and hard X-ray photoelectron spectroscopies, as well as Superconducting Quantum Interference Device measurements. The Fe-induced pattern differs from those of both reference systems since a pattern displaying short hexagonal ordering develops, although it shares some features with them. In both Fe systems a chemical pattern, with iron silicide-rich and -poor regions, is formed upon prolonged irradiation. The metal pathway has a marked influence on the patterns' morphological properties and on the spatial correlation between the chemical and morphological patterns. It also determines the iron silicide stoichiometry and the surface pattern magnetic properties that are better for the Fe-implanted system. These results show that in ion-beam-induced silicon surface patterning with reactive metals, the metal supply pathway is critical to determine not only the morphological pattern properties, but also the chemical and magnetic ones. [ABSTRACT FROM AUTHOR]

Highlights: [•] Standard behavioral tests were successfully applied to NPC1−/− mutant mice. [•] The mutant mice revealed defective motor performance and cognitive impairment. [•] The motor impairment was in agreement with Purkinje cell degeneration in the cerebellum. [•] The motor performance improved significantly upon combined therapy. [•] The impaired cognitive function, however, did not benefit from the treatment. [Copyright &y& Elsevier]