We have developed a new depth-graded multilayer system comprising W and SiC layers, suitable for use as hard x-ray reflective coatings operating in the energy range 100-200 keV. Grazing-incidence x-ray reflectance at E = 8 keV was used to characterize the interface widths, as well as the temporal and thermal stability in both periodic and depth-graded W/SiC structures, whereas synchrotron radia...

The (001) surfaces of cubic SiC were investigated with ab-initio molecular dynamics simulations. We show that C-terminated surfaces can have different c(2×2) and p(2×1) reconstructions, depending on preparation conditions and thermal treatment, and we suggest experimental probes to identify the various reconstructed geometries. Furthermore we show that Si-terminated surfaces exhibit a p(2×1) re...

We compare the reflectance and stability of multilayers comprising either Si/Mo, Si/Mo2C, Si/B4C, Si/C, or Si/SiC bilayers, designed for use as extreme-ultraviolet (EUV) reflective coatings. The films were deposited by using magnetron sputtering and characterized by both x-ray and EUV reflectometry. We find that the new Si/SiC multilayer offers the greatest spectral selectivity at the longer wa...

We propose structural and electronic properties of recently synthesized SiC nanotubes. The nanotubes with a Si to C ratio of 1:1 exhibit rich morphologies and are shown to belong to two distinct categories that are close in energies but show significant differences in electronic and transport properties. Similarities and differences are invoked with the case of BN nanotubes to explain the obser...

In this paper, we study the electrochemical anodization of n-type heavily doped 4 H-SiC wafers in a HF-based electrolyte without any UV light assistance. We present, in particular, the differences observed between the etching of Si and C faces. In the case of the Si face, the resulting material is mesoporous (diameters in the range of 5 to 50 nm) with an increase of the 'chevron shaped' pore de...

Drag reduction has become a serious issue in recent years in terms of energy conservation and environmental protection. Among diverse approaches for drag reduction, superhydrophobic surfaces have been mainly researched due to their high drag reducing efficiency. However, due to limited lifetime of plastron (i.e., air pockets) on superhydrophobic surfaces in underwater, the instability of dewett...

A series of 3C-SiC films have been grown by a novel method of solid-gas phase epitaxy and studied by Raman scattering and scanning electron microscopy (SEM). It is shown that during the epitaxial growth in an atmosphere of CO, 3C-SiC films of high crystalline quality, with a thickness of 20 nm up to few hundreds nanometers can be formed on a (111) Si wafer, with a simultaneous growth of voids i...

China recently surpassed Japan as the world's second largest automobile market after the United States. Annual output of automobiles is close to six million units a year. A key tool in automotive production is the spot welding gun and the industrial robot. One of the most important parameters of a spot welding gun is force tolerance. ABB is helping the Chinese automotive industry improve weldin...

Biomorphic silicon carbide stands as a new class of materials fabricated by reactive infiltration of molten silicon in carbonaceous preforms obtained from wood pyrolysis [1]. The basic material is a Si/SiC composite, in which the SiC forms a skeleton that replicates the wood microstructure and the unreacted Si fills the pores. Silicon can be removed from the composite creating a highly porous S...