field ion microscopy (fim) and scanning tunneling microscopy (stm) have found a wide application in nanotechnology. these microscopes use a metallic nanotip for image acquisition. resolution of fim and stm images depends largely on the radius of nanotip apex; the smaller the radius the higher the resolution. in this research, for tungsten nanotip fabrication, electrochemical etching of tungsten...

Efficient visible light-induced photoelectrochemical oxidation of water was achieved using a tungsten(iv) oxide (WO(3)) film composed of perpendicularly oriented plate-like crystallites, a flake-wall film, prepared on a transparent conductive substrate by controlling anisotropic crystal growth of tungsten oxide hydrate (WO(3).H(2)O) followed by calcination.

Process This chapter presents the principle of tungsten inert gas (TIG) welding process besides important components of TIG welding system and their role. This process is also known as gas tungsten arc welding (GTAW) process. Further, fundamentals of heat generation, arc stability and arc efficiency have also been described. Additionally, comparison of argon and helium as shielded gases has bee...

Among transition metal oxides, tungsten trioxide is one of the most interesting materials exhibiting a wide variety of novel properties particularly in thin film form useful for advanced technological applications. It exhibits structural transformations and substoichiometric phase transitions, which attracted the attention of researchers over the past few years to explore their potential scient...

We report growth of tungsten diselenide (WSe2) nanotubes by chemical vapor deposition with a two-zone furnace. WO3 nanowires were first grown by annealing tungsten thin films under argon ambient. WSe2 nanotubes were then grown at the tips of WO3 nanowires through selenization via two steps: (i) formation of tubular WSe2 structures on the outside of WO3 nanowires, resulting in core (WO3)-shell (...

Coupled exfoliation and fracture induced formation of hydrophobic monolayered nanoflakes in a nonpolar organic medium. The hydrophobic monolayered nanoflakes 5-20 nm in lateral size consisted of a tungstate layer with surface modification by stearylammonium ions (C18H37NH3)0.397 H0.603Cs3W11O35·xH2O (x < 0.625).

Contrary to the conventional understanding that atomic clusters usually differ in properties and structure from the bulk constituents of which they are comprised, we show that even a dimer of tungsten oxide (WO(3))(2) possesses bulklike features and the geometry of a small cluster containing only 4 tungsten and 12 oxygen atoms bears the hallmarks of crystalline tungsten oxide, WO(3). This obser...

The dynamics of the local electronic and geometric structures of WO3 following photoexcitation were studied by femtosecond time-resolved X-ray absorption fine structure (XAFS) spectroscopy using an X-ray free electron laser (XFEL). We found that the electronic state was the first to change followed by the local structure, which was affected within 200 ps of photoexcitation.

Photoluminescence measurements showed that needle-like tungsten oxide nanostructures synthesized at 590°C to 750°C by the thermal evaporation of WO3 nanopowders without the use of a catalyst had an intense near-ultraviolet (NUV) emission band that was different from that of the tungsten oxide nanostructures obtained in other temperature ranges. The intense NUV emission might be due to the local...