Vaporization thermal evaporation

The formation of clusters in the gas phase involves eondensation of the vapom of the constituents, with the exeeption of the electrospray source [6], where ion-solvent clusters are produced directly from a liquid solution. For rare gas or molecular clusters, supersonic beams are used to initiate cluster formation. For nonvolatile materials, the vapours can be produced in one of several ways including laser vaporization, thermal evaporation and sputtering. 

Zinc Costing of Ca.pa.citors, In the zinc coating of paper strip for capacitors, the paper strip is fed from air through locks into a vacuum environment. There, it is coated by thermally evaporated zinc. The rate of evaporation is so high that contamination of the zinc vapor is excluded. The paper is fed at the maximum rate permitted by its own strength. 

Substances with high vapor pressure evaporate rapidly. Those with low vapor pressure evaporate slowly. The impact of vapor pressure on the rate of evaporation makes vapor pressure a very important property in considering the tactical use and duration of effectiveness of chemical agents. A potential chemical agent is valuable for employment when it has a reasonable vapor pressure. One with exceptionally high vapor pressure is of limited use. It vaporizes and dissipates too quickly. Examples are arsine and carbon monoxide. On the other hand, mechanical or thermal means may effectively aerosolize and disseminate solid and liquid agents of very low vapor pressure. Vapor pressure and volatility are related. Translated into volatility, vapor pressure is most understandable and useful. 

The other platform is dielectrics, for example, silicon dioxide, silicon nitride, silicon oxynitride, tantalum pentoxide, and titanium dioxide. They can be deposited by various methods, such as plasma-enhanced chemical vapor deposition, thermal evaporation, electron-beam evaporation, and sputtering. There are a number of dielectrics with refractive indices ranging from 1.45 to 2.4, facilitating diverse waveguide designs to satisfy different specification. Dielectrics have two other... 

A striking feature of the ILs is their low vapor pressure. This, on the other hand, is a factor hampering their investigation by MS. For example, a technique like electron impact (El) MS, based on thermal evaporation of the sample prior to ionization of the vaporized analyte by collision with an electron beam, has only rarely been applied for the analysis of this class of compounds. In contrast, nonthermal ionization methods, like fast atom bombardment (FAB), secondary ion mass spectrometry (SIMS), atmospheric pressure chemical ionization (APCI), ESI, and MALDI suit better for this purpose. Measurement on the atomic level after burning the sample in a hot plasma (up to 8000°C), as realized in inductively coupled plasma (ICP) MS, has up to now only rarely been applied in the field of IE (characterization of gold particles dissolved in IE [1]). This method will potentially attract more interest in the future, especially, when the coupling of this method with chromatographic separations becomes a routine method. 

I. Methods of Reacting Atoms and Compounds CC Cocondensation of the vapor of a compound and a metal vapor formed by thermal evaporation of a metal... 

Fabrication methods include thermal evaporation, sputtering, magnetron sputtering, pulsed laser evaporation, molecular beam epitaxy, chemical vapor deposition, electrolytic and electroless deposition, and growth from solution. 

Formation of metal clusters by gas aggregation, in which metal atoms are evaporated or sputtered into a cooled inert gas flow at relatively high pressure, has been well established in last decade. By repeated collisions with the carrier gas, the supersaturated metal vapor nucleates and forms clusters. The mechanism of cluster formation can be explained with homogeneous and heterogeneous nucleation theories. The gas aggregation methods have been applied extensively to produce small clusters of metals such as zinc, copper, silver etc. [23-26]. In some cases this method was used in combination with a mass filter such as a quadruple or a time-of-flight spectrometer [27, 28], The metal vapor for cluster source can be produced by either thermal evaporation [23-28] or sputter discharge [22, 29]. 

Atp > 500 mTorr, larger particles were able to agglomerate in the vapor phase, which lead to a particle size/pressure correlation similar to that observed in thermal evaporation with p> 1 Torr. 

Evaporation is suitable for all metals (the most refractory metals cannot be thermally evaporated, but can be e-beam evaporated), a few sublimable organic and organometallic compounds such as the phthalocyanines, and a relatively small number of inorganic dielectric materials, such as Mgp2 and SnC>2. Nearly all polymers decompose in one manner or another before a high enough temperature is obtained for them to become mobile in the vapor phase. 

Fabrication of most components in state of the art devices is done using vapor deposition techniques, such as thermal evaporation or CVD. Solution deposition of a polymer layer in the device could be an elaborate, expensive and slow step. CVD of polymers simplifies device integration and enables substantial reduction in the complexity of the manufacturing process. 

Vapor deposition. Both physical and chemical vapor deposition methods can be used to prq)are dense inorganic membranes. In either process, vaporization of the membrane material to be deposited is effected by physical means (such as thermal evaporation and sputtering) or chemical reactions. 

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