Consolidation behavior of Mo powder fabricated from milled Mo oxide by hydrogen-reduction

Densification behavior of Mo nanopowders prepared by mechanochemical processing

“…MoO 3 powder was high-energy ball-milled at a milling speed of 400 rpm in an Ar atmosphere for 20 h with a Simoloyer, which is a horizontal-type attrition mill. The ball-milled MoO 3 powder was reduced under non-isothermal conditions up to a temperature of 800 • C with a heating rate of 10 • C/min in an H 2 atmosphere with a dew point of −76 • C. As previously reported, the particle size of Mo powder synthesized by this process was about 100 nm [14].…”

Kinetic Studies on Hydrogen Reduction of MoO3 and Morphological Analysis of Reduced Mo Powder

“…The reduction takes place in two stages: first, MoO 3 is converted to MoO 2 ; and, second, MoO 2 is converted to Mo. [5] Formation of an intermediate oxide Mo 4 O 11 during the first stage has also been reported in the literature. [6,7] The mechanism of the reaction is described best by the classical gas-solid reaction model, namely, the shrinking core model (SCM), [8] which describes a shrinking core of unreacted solid, surrounded by a growing layer of product during the reaction of a solid particle with gas.…”

Sensing Properties of WO₃ as Thin Film Prepared by PVD towards Methanol Vapor

“…The I-V characteristics for each prepared film is studied in air and in 100 ppm of methanol vapor at different temperature ( 25-350 C) drawn as follows: We notice from the previous figures that all thin films are affected by change of applied temperatures during the measurements, and have an ohmic resistance, as increasing the temperature as increasing the current from A at 25C to a few parts of mA at 350C, and from these figures we can calculate the resistance in air and in 100 ppm of methanol vapor as follows: When we draw the sensitivity as a function of temperature for three thin films (998.7, 1620, 2240 nm) as follows: Figure 4 Sensitivity as a function of temperature for three thin films of WO 3 We notice that the sensitivity of WO 3 thin film which has 1620 nm as a thickness was increasing by increasing of temperature to reach a high value 214.29%at 250 C then it was decreasing by increasing of temperature so, we can say that a 250 C is an operating degree for this film, and we can see the same thing for the WO 3 thin film which has 2240 nm as a thickness but the WO 3 film (998.7 nm ) as a thickness increase of temperature as increase of sensitivity intill 350°C but not over 100%.…”