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Tantalum ores often contain significant amounts of niobium, which is itself a valuable metal.As such, both metals are extracted so that they may be sold. The overall process is one of hydrometallurgy and begins with a leaching step; in which the ore is treated with hydrofluoric acid and sulfuric acid to produce water-soluble hydrogen fluorides, such as the heptafluorotantalate.
Mixed-metal thin-films have also been prepared from this compound. For example, lithium tantalate, LiTaO 3 , films are desirable for their non-linear optical properties and have been prepared by first reacting tantalum(V) ethoxide with lithium dipivaloylmethanate, LiCH(COC(CH 3 ) 3 ) 2 , to prepare a precursor suitable for metalorganic vapour ...
A productive overview is provided by several exceptional reviews covering fields of MOCVD such as, for instance, epitaxial growth of semiconductor compounds, [2] [3] [4] and low temperature deposition of metals. [5] [6] An overview of metal-organic compounds used for the MOCVD growth of different kind of materials is reported in the following ...
These metals can form useful silicides when deposited onto silicon. Mo, Ta and Ti are deposited by LPCVD, from their pentachlorides. Nickel, molybdenum, and tungsten can be deposited at low temperatures from their carbonyl precursors. In general, for an arbitrary metal M, the chloride deposition reaction is as follows: 2 MCl 5 + 5 H 2 → 2 M ...
Vacuum deposition is a group of processes used to deposit layers of material atom-by-atom or molecule-by-molecule on a solid surface. These processes operate at pressures well below atmospheric pressure (i.e., vacuum ).
Physical vapor deposition (PVD), sometimes called physical vapor transport (PVT), describes a variety of vacuum deposition methods which can be used to produce thin films and coatings on substrates including metals, ceramics, glass, and polymers. PVD is characterized by a process in which the material transitions from a condensed phase to a ...
In the metal organic chemical vapor deposition (MOCVD) technique, reactant gases are combined at elevated temperatures in the reactor to cause a chemical interaction, resulting in the deposition of materials on the substrate. A reactor is a chamber made of a material that does not react with the chemicals being used.
In chemistry, deposition occurs when molecules settle out of a solution. Deposition can be defined as the process of direct transition of a substance from its gaseous form, on cooling, into a solid state without passing through the intermediate liquid state. [1] Deposition can be viewed as a reverse process to dissolution or particle re ...