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A newly designed gas phase thermal decomposition reactor, ohmically heating the catalytic sites, has been used to synthesize multiwall carbon nanotubes (MWCNTs) on carbon paper and stainless steel screen. Co-Ni catalyst particles were dispersed by a silane intermediate layer adsorbed onto the carbon fibers or the stainless steel threads of the supports. MWCNTs were obtained on both substrates by a tip grown mechanism. They are about 20 μm in length and 15–50 nm in diameter. A methanol pretreatment of the carbon fibers significantly increased the density of the tubes on the carbon paper, but the same treatment had a negative effect on stainless steel. The MWCNTs, which adhere firmly to the carbon paper and the stainless steel screen, may find applications as electrodes in fuel cells, sensors and in photonics.

It is believed that carbon nanotubes were not able to grow on silicon substrates by chemical vapor deposition from a mixture of ferrocene and xylene. This is because iron particles (formed by the decomposition of ferrocene) reacted quickly with silicon to form a discontinuous layer (> 100 nm) of FeSi₂ and Fe₂SiO₄ particles. We report, in this letter, that by controlling the growth kinetics, aligned carbon nanotubes could be grown on pristine silicon substrates. The reason is that appropriate growth conditions could slow down and suppress the reaction within the very surface region to form an almost continuous thin layer (< 10 nm) of Fe₂SiO₄ particles; thus preventing further reaction and leaving a number of iron particles still active to catalyze the growth of carbon nanotubes. The structure and field emission properties of the nanotubes were also investigated.

A technique was investigated for the fabrication of triode-type carbon nanotube (CNT) field emitter arrays, where an integrated extraction gate was built between the nanotube cathode and the anode. The gate improves the control capability of emission currents. To fabricate the metal-gated CNT field emitter arrays, well ordered cells were generated by focused ion beam (FIB) milling of platinum (Pt) coated silicon (Si) substrate and then modified by chemical etching. Two types of catalyst elements iron (Fe) and nickel (Ni), were used for growing the CNTs inside the cells. The methods for depositing catalysts into the cells include spin coating sol–gel Fe, FIB induced decomposition of ferrocene and sputter coating pure Ni. CNT growth was carried out by a chemical vapor deposition (CVD) process. The results suggest that the CNTs grew from inside the cells where the catalysts were located. In comparison, the CNTs synthesized from the sol–gel Fe catalyst were straighter than those from ferrocene Fe and pure Ni. The density and orientation of the CNTs in each cell are directly related to the type and quantity of the catalysts and are also affected by the size of the cells.

MoS₂ films on sapphire and SiO₂/Si substrates were fabricated by sulfurization of sputtered Mo precursor films at 900^∘C in a two-zone furnace. Structural, morphological, optical and electrical properties of the films were determined. The films of MoS₂ were successfully grown on the substrates with polycrystalline structures and proposed to be used in electro-optical devices.

In this paper, the effect of hydrogen embrittlement in High-strength low-alloy steel (HSLA) material was studied. HSLA steels are known for their susceptibility to hydrogen induced failure especially when subjected to hydrogen rich environment. In this research, samples from HSLAS were surface-treated using chemical vapor deposition (CVD) techniques, followed by direct Zinc coating using physical vapor deposition (PVD). Other samples were additionally post-heat treated at a temperature of 260^∘C for 4h to optimize the coating process. The hydrogen embrittlement test was performed by immersing the tensile samples in a solution containing H₂SO₄ diluted with water for 24h. Hardness, and mechanical properties were evaluated using tensile testing. XRD and SEM were used for microstructural and topographical features’ examination of the treated samples. The results indicate that the samples of combined $\mathrm{\text{PVD}}+\mathrm{\text{CVD}}$ coating that was backed at 260^∘C show superior resistance to hydrogen embrittlement compared to other conditions. This could be attributed to the buildup of a strong outer layer that prevents hydrogen from diffusing towards the base HSLAS material. The greater mechanical properties are possibly due to the reduction of hydrogen amount generated by the surface reaction associated by the formation of Zn(N${}_3{)}_2$ phase and the reduction of hydrogen amount passed through Zn and C₃N₄ layers.