Results 201 to 210 of about 12,953 (259)
Chem Commun (Camb)Some of the next articles are maybe not open access.
Related searches:
Related searches:
Tungsten Oxide Nanowires on Tungsten Substrates
Nano Letters, 2002A simple method was discovered to prepare tungsten oxide nanowires directly from tungsten metal. The structure and composition of the nanowires were characterized by high resolution tunneling electron microscopy (HRTEM) and energy dispersive X-ray scattering (EDX), respectively.
Gu, G. +4 more
openaire +2 more sources
Sequential oxidation and reduction of tungsten/tungsten oxide
Thin Solid Films, 2015Abstract The reduction of oxide films on the surface of tungsten was studied. The oxide films were created by briefly exposing smooth W foils to oxygen plasma generated using a microwave discharge at 500 W and an oxygen pressure of 40 Pa. Oxidation resulted in the formation of a WO3 film with a thickness of approximately 1700 nm. The oxidised samples
Vesel, Alenka +2 more
openaire +2 more sources
Journal of The Electrochemical Society, 1956
Two oxide layers form during the oxidation of tungsten between 700° and 1000°C. The outer layer is porous, powdery, yellow tungstic oxide, , and the inner layer is a dense, thin, dark‐blue, tightly adherent oxide of uncertain composition. The oxidation reaction follows initially the parabolic rate law, but eventually there is a transition to the linear
Watt W. Webb +2 more
openaire +1 more source
Two oxide layers form during the oxidation of tungsten between 700° and 1000°C. The outer layer is porous, powdery, yellow tungstic oxide, , and the inner layer is a dense, thin, dark‐blue, tightly adherent oxide of uncertain composition. The oxidation reaction follows initially the parabolic rate law, but eventually there is a transition to the linear
Watt W. Webb +2 more
openaire +1 more source
Reduction of tungsten oxide to tungsten metal
Metallurgical Transactions B, 1976Tungsten oxide, WO2.96, was reduced toα-W in hydrogen for various time periods over the temperature range 500°C to 900°C. Intermediate oxides were determined using X-ray diffraction analysis of the semireduced powders. Several dopant conditions were used, to find the effect on oxide structures and reaction kinetics of the usual dopants K, Si and Al ...
Theodore R. Wilken +3 more
openaire +1 more source
Chemistry of Tungsten Oxide Bronzes
International Journal of Refractory Metals and Hard Materials, 1995Abstract Ammonium paratungstate (APT) is the generally accepted starting material in tungsten manufacturing. The dopants, which are responsible for the non-sag properties, are given to some tungsten oxide bronze (TOB)-type compounds which are formed by thermal reductive decomposition of APT.
L. Bartha, A.B. Kiss, T. Szalay
openaire +1 more source
A study of iron–tungsten oxides and iron–chromium–tungsten oxides
Canadian Journal of Chemistry, 1988A 57Fe Moessbauer study of the Fe2O3–WO3 and Fe2O3–Cr2O3–WO3 systems has been carried out. Single phase materials could be prepared having the composition Fe2−xWO6−3x/2 (x = 0.28), the stoichiometric Fe2WO6 always contained detectable amounts of α-Fe2O3. The iron tungstates are found to be unstable to prolonged heating at 1000 °C.
Thomas Birchall +3 more
openaire +1 more source
Spectrographic determination of impurities in ultrapure tungsten and tungsten oxide
Talanta, 1975The effects of an external magnetic field and of the diameter of the anode on the spectroscopic line intensity of the impurity elements in ultrapure tungsten and tungsten oxide have been studied. The results obtained are used for the development of a more sensitive method for the determination of these impurities (Mn, Pb, Fe, Ni, Al, Mo, V, Cu, Cr).
Y, Harizanov, N, Jordanov
openaire +2 more sources
Controlled Synthesis of Tungsten and Tungsten Oxide Nanorod Films
Materials Research Innovations, 2006AbstractTungsten and tungsten oxide films were deposited in a hot filament reactor under flowing argon atmosphere at various filament temperatures, followed by the characterization via scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD).
Weifeng Chen +4 more
openaire +1 more source
Preparation of Nanosized Tungsten and Tungsten Oxide Powders
Physics of the Solid State, 2018Nanopowder tungsten oxide and metallic tungsten are obtained via pyrolysis of ammonium metatungstate. Two methods are used for the synthesis of tungsten oxide: the use of a fibrous matrix and pyrolysis of aerosol particles. Tungsten oxide particles are formed during the pyrolysis in air.
Kh. A. Abdullin +5 more
openaire +1 more source