Rubidium alloy

Olher mudern getter materials include cesium-rubidium alloys, tantalum. titanium, zirconium, and several of the rare-earth elements, such as hafnium,... 

Rubidium alloys easily with potassium, sodium, silver, and gold, and forms amalgams with mercury. Rubidium and potassium arc completely miscible 111 the solid state. Cesium and rubidium form an uninterrupted series of solid solutions. These alloys, in various combinations, are used mainly as getters for removing the last traces of air in htgh-vacmim devices and systems. 

Rubidium alloys used in research to mimic the properties of caesium, a rarer metal. 

Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali group and is the second most electropositive and alkaline element. It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere. 

Rubidium metal alloys with the other alkaU metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double haUde salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and 2iac. These complexes are generally water iasoluble and not hygroscopic. The soluble mbidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide. 

With potassium or antimony, the interaction gives rise to a small deflagration. With lithium at 200°C, the reaction is violent. With rubidium, the mixture combusts. The action of iodine on titanium or the Ti-AI alloy enables one to prepare titanium diodide. The reaction, which is carried out above 113 C under reduced pressure or at 360 C under normal pressure is violent and produces showers of sparks. 

Mercury forms amalgams with numerous metals. Usually, this conversion is very exothermic, therefore it can present risks the reaction can become violent if a metai is added too quickly into mercury. Accidents have been described with caicium (at 390°C), aluminium, alkali metals (lithium, sodium, potassium, rubidium) and cerium. Some of these alloys are very inflammable, in particular the Hg-Zn amalgam. 

Bonilla, C. F., D. L. Sawhuey, and N. M. Makansi, 1962, Vapor Pressure of Alkali Metals III, Rubidium, Cesium, and Sodium-Potassium alloy up to 100 psia, Proc. 1962 High Temperature Liquid MetaI Heat Transfer Tech. Meeting, BNL-756, Brookhaven, NY. (3)... 

Rubidium hydroxide, 27 821-822 Rubidium iodide, 27 823 Rubidium metal alloys, 27 816 Rubidium metal, pure, 27 818 Rubidium oxides, 27 816, 823 Rubidium ozonide, 78 417 Rubidium silicates, 22 452 Rubidium sulfate, 27 821 Rubidium superoxide, 78 417 Rubidium tetrahydroborate physical properties of, 4 194t Ruby, 2 405 color, 7 329 Ruby glass, 7 344... 

The collected papers of a symposium at Dallas, April 1956, cover all aspects of the handling, use and hazards of lithium, sodium, potassium, their alloys, oxides and hydrides, in 19 chapters [1], Interaction of all 5 alkali metals with water under various circumstances has been discussed comparatively [2], In a monograph covering properties, preparation, handling and applications of the enhanced reactivity of metals dispersed finely in hydrocarbon diluents, the hazardous nature of potassium dispersions, and especially of rubidium and caesium dispersions is stressed [3], Alkaline-earth metal dispersions are of relatively low hazard. Safety practices for small-scale storage, handling, heating and reactions of lithium potassium and sodium with water are reviewed [4],... 

One problem in refining cesium is that it is usually found along with rubidium therefore, the two elements must be separated after they are extracted from their sources. The main process to produce cesium is to finely grind its ores and then heat the mix to about 600°C along with liquid sodium, which produces an alloy of Na, Cs, and Ru, which are separated by fractional distillation. Cesium can also be produced by the thermochemical reduction of a mixture of cesium chloride (CsCl) and calcium (Ca). 

In 1988, Cava and co-workers also prepared (88a) a quaternary oxide, Ba/K/Bi/O, and observed superconductivity at -28 K. This compound was the first "non-transition metal" oxide with a Tc above the legendary "alloy record" of 23 K. Further studies indicated (88a) that the optimum composition for "high temperature" superconductivity in this system was Ba0 6K0 4BiO3 x, having a Tc of 30.5 K (Figure 17). The samples were multiphase, and the superconducting fraction varied from 3 to 25%. Superconductivity for the rubidium-substituted compound was observed at -28.6 K. 

Metals and Alloys—Rubidium, File No. 320-PD-l, KB I Division of Cabot Corp., Reading, Pa. 

Molten sodium and potassium hydroxides are completely miscible in all proportions, and the f.p. curve has a minimum at 187° with a mixture containing 38 7 atomic percent, of KOH, that is, 48 97 per cent, of KOH by weight. The transformation temp, of the cooling solid alloys furnish a curve similar in form to the f.p. curve, and the solid eutectic has a transformation point at 181°., Mixtures of potassium and rubidium hydroxides are completely miscible, and they give a curve with two maxima-, one rises from the m.p. of potassium hydroxide 360-4° up to 399° with 87 atomic per cent, of KOH, and the other from the m.p. of rubidium hydroxide... 

Cesium forms several solid solutions with rubidium. These alloys are used as getters for eliminating residual gases from vacuum tubes and... 

Magnesium—nickel hydride, 4458 Plutonium(III) hydride, 4504 Poly(germanium dihydride), 4409 Poly(germanium monohydride), 4407 Potassium hydride, 4421 Rubidium hydride, 4444 Sodium hydride, 4438 f Stibine, 4505 Thorium dihydride, 4483 Thorium hydride, 4535 Titanium dihydride, 4484 Titanium—zirconium hydride, 4485 Trigermane, 4415 Uranium(III) hydride, 4506 Uranium(IV) hydride, 4536 Zinc hydride, 4486 Zirconium hydride , 4487 See COMPLEX HYDRIDES, PYROPHORIC MATERIALS See entry LANTHANIDE—TRANSITION METAL ALLOY HYDRIDES... 

Moissan 7 found that the hydrides of lithium, sodium, potassium, rubidium, and caesium are non-conductors of electricity, and therefore cannot be regarded as alloys. He considered that in these compounds hydrogen has a metalloidic character, and that it is not comparable with the metals, an argument against its inclusion in Group I.8... 

SAFETY PROFILE A highly corrosive irritant to the eyes, skin, and mucous membranes. Mildly toxic by inhalation, Explosive reaction with alcohols + hydrogen cyanide, potassium permanganate, sodium (with aqueous HCl), tetraselenium tetranitride. Ignition on contact with aluminum-titanium alloys (with HCl vapor), fluorine, hexa-lithium disilicide, metal acetylides or carbides (e.g., cesium acetylide, rubidium ace-tylide). Violent reaction with 1,1-difluoro-ethylene. Vigorous reaction with aluminum, chlorine + dinitroanilines (evolves gas). Potentially dangerous reaction with sulfuric acid releases HCl gas. Adsorption of the acid onto silicon dioxide is exothermic. See also HYDROGEN CHLORIDE (AEROSOL) and HYDROCHLORIC ACID. 

Methylpotassium, prepared from MeHg and K/Na alloy or from methyllithium and potassium r-butox-ide, has a hexagonal structure corresponding to the NiAs type (59). Each methyl group is considered to be coordinated to six K ions in a trigonal prismatic array. Methylrubidium and methylcesium, prepared from rubidium r-butoxide and cesium 2-methylpentanoate respectively, also possess hexagonal structures of the same type as methylpotassium. ... 

The results have been reported of a comparative study of the measured electrical resistivities of liquid alkali metals and alloys, and the theoretical predictions for this quantity obtained within the diffraction model.48 The composition dependence of the Knight shifts in Na-Cs, Na-Rb, K-Rb-Cs, and Na-Rb-Cs liquid alloys has also been examined.49 Addition of small quantities of rubidium (0.3—4.51 atom %) to liquid sodium increases the electrical resistivity almost linearly with increasing solute concentration. With increasing temperature from 100 to 1100 °C, the effect of rubidium on the resistivity of sodium progressively diminishes.50 Addition of the solutes Hg, Tl, and Pb increases the resistivity of liquid potassium linearly with both increasing concentration and temperature. The unit increases in resistivity/pfl cm (atom%) , are 8.80, 9.85, and 15.8 for Hg, Tl, and Pb,... 

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