Palladium catalysts containing Pd(II) supported on Al2O3 and alumina-based mixed oxides, Al2O3-ZrO2, Al2O3-CeO2, and Al2O3-Fe2O3, are very effective in the Heck coupling of iodobenzene with cyclohexene in DMF solution. The best results, up to 81% of monoarylated products with a selectivity to 4-phenylcyclohexene (3) close to 90% were obtained with KOH as a base. The catalytic activity of pallad...

We report on our investigation of the electrical properties of metal/Al2O3/GaN metal-insulatorsemiconductor capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing the capacitance-voltage characteristics of atomic layer deposited Al2O3 films on GaN substrates. The conduction band offset at the Al2O3/GaN interface was calculated...

Growth of reactively co-sputtered Al2O3 layers and micro-structuring using reactive ion etching have been optimized, resulting in channel waveguides in the as-deposited layers with optical propagation losses as low as 0.21 dB/cm. For active functionality, Erdoped Al2O3 layers have also been deposited by co-sputtering from a metallic Er target. At relevant dopant levels (~10 cm) lifetimes of the...

X-ray photoelectron spectroscopy was applied to study the hydroxylation of a-Al2O3 (0001) surfaces and the stability of surface OH groups. The evolution of interfacial chemistry of the a-Al2O3 (0001) surfaces and metal/a-Al2O3 (0001) interfaces are well illustrated via modifications of the surface O1s spectra. Clean hydroxylated surfaces are obtained through waterand oxygen plasma treatment at ...

We have developed a two-step growth scheme for single-crystal Al2O3 tunnel barriers. The barriers are epitaxially grown on single-crystal rhenium (Re) base electrodes that are grown epitaxially on a sapphire substrate, while polycrystalline Al is used as the top electrode. We show that by first growing an amorphous aluminum (Al) oxide layer at room temperature and crystallizing it at a high tem...

An egg-shell Pd/Al2O3 catalyst showed higher activity than a regular Pd/Al2O3 catalyst in the partial oxidation of methane to syngas, but a common problem of this reaction is the catalyst deactivation on stream. We attempted to modify the egg-shell catalyst via impregnation with some metal oxide additives. Although the addition of MgO did not show any beneficial effect, the addition of CaO and/...

This paper is concerned with the investigation of the capability of Detonation sprayed Ni-Cr And Al2O3 13TiO2 coatings to improve the tribological and mechanical properties of grey cast iron. The present study describes and compares the mechanical and tribological properties of NiCr and Al2O3 13TiO2 D-Sprayed coatings deposited on two different substrates (GI250 and GIHC) Experiments using a tr...

Silicon carbide (SiC) has shown considerable potential for ultraviolet (UV) photode‐ tectors due to its properties such as wide band gap (3.26 eV for 4H-SiC), high break down electric field and high thermal stability. 4H-SiC-based UV photodetectors such as Schottky, metal-semiconductor-metal (MSM), metal-insulator-semiconductor (MIS) and avalanche have been presenting excellent performance for ...