Metallic melt deposition

Run the metal melted or deposited during one passage of an electrode, torch or blow-pipe. 

The element revealed itself through spectacular violet-colored flames and several red spectral lines. The metal melts at 38 °C, is very soft, and extremely reactive (burns in air and reacts violently with water). Rubidium is stored under mineral oil. It is suitable as a scavenger (oxygen capture) in vacuum tubes, where it is deposited on the glass as a mirror. It can also be found in photocells and phosphors for screens (for example, for air-traffic controllers. Not physiologically important. The radioactive rubidium-87 is useful for age determination in geochronology (half-life ca. 50 billion years). 

If an actinide metal is available in sufficient quantity to form a rod or an electrode, very efficient methods of purification are applicable electrorefining, zone melting, and electrotransport. Thorium, uranium, neptunium, and plutonium metals have been refined by electrolysis in molten salts (84). An electrode of impure metal is dissolved anodically in a molten salt bath (e.g., in LiCl/KCl eutectic) the metal is deposited electrochemically on the cathode as a solid or a liquid (19, 24). To date, the purest Np and Pu metals have been produced by this technique. 

Cadmium also may be recovered from zinc ores and separated from other metals present as impurities by fractional distillation. Alternatively, the cadmium dust obtained from the roasting of zinc ore is mixed with sulfuric acid. Zinc dust is added in small quantities to precipitate out copper and other impurities. The metal impurities are removed by filtration. An excess amount of zinc dust is added to the solution. A spongy cadmium-rich precipitate is formed which may he oxidized and dissolved in dilute sulfuric acid. Cadmium sulfate solution is then electrolyzed using aluminum cathodes and lead anodes. The metal is deposited at the cathode, stripped out regularly, washed and melted in an iron retort in the presence of caustic soda, and drawn into desired shapes. More than half of the world s production of cadmium is obtained by elecrolytic processes. 

Reactions of carboxylates containing the more electropositive cations yield product carbonates, or sometimes the basic carbonates. Some of these salts, e.g., those of the alkali metals, melt before decomposition. The oxide products from decomposition of the lanthanide compounds may contain carbon deposited as a result of carbon monoxide disproportionation. Kinetic measurements must include due consideration of the possible retention of carbon dioxide by the product (as COj ) and the secondary reactions involved in carbon deposition. 

For films produced by evaporative techniques, it is approximately true that with metal films deposited on a substrate at room temperature and even higher, tensile stresses are predominant. The magnitude of the tensile stresses is between 108 and 10 dyn cm 2. Films of high-melting metals have the larger values, those of lower melting metals the smaller values in this range. Reactively sputter deposited dielectric films and metal films modified by chemical and/or physical gas incorporation frequently have compressive stresses. Compared with metal films, dielectric films often have smaller stress values. 

With some of the other rare earth metals (Sc, Gd), it is necessary to work below the melting point of the metal. In such cases the metal is deposited on a cathode ofmolten Zn or Cd, in which the metal dissolves. The Zn or Cd is vacuum-distilled from the product alloy. 

During MPC discharge the dispersed tungsten powder was injected into the plasma flow. Melted metal particles were transported to the target by the flow. Metal particles deposition took place at the final stage of compression plasma flow existence [2]. The samples were treated by one and three plasma pulses (n). 

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