Barium calcium copper strontium thallium

BiCaCu207Sr2Tl, Barium calcium copper strontium thallium oxide ((Ba,Tl)CaCu2Sr207). (158188-92-2], 30 204... 

Research chemists found that they could modify the conducting properties of solids by doping them, a process commonly used to control the properties of semiconductors (see Section 3.13). In 1986, a record-high Ts of 35 K was observed, surprisingly not for a metal, but for a ceramic material (Section 14.24), a lanthanum-copper oxide doped with barium. Then early in 1987, a new record T, of 93 K was set with yttrium-barium-copper and a series of related oxides. In 1988, two more oxide series of bismuth-strontium-calcium-copper and thallium-barium-calcium-copper exhibited transition temperatures of 110 and 125 K, respectively. These temperatures can be reached by cooling the materials with liquid nitrogen, which costs only about 0.20 per liter. Suddenly, superconducting devices became economically viable. 

Rosenberg [63] investigated the properties of sodium, potassium, calcium, strontium, barium, cadmium, cupric, copper, manganese, thallium and silver fulminates and compared them with mercury fulminate. Some of this results are shown in Table 24. 

The trimethylsilylated silicic acids formed in this instance are soluble in conventional organic solvents, and their volatility is sufficiently high for them to be analysed by gas chromatography. Carzo and Hoebbel [411] carried out a comprehensive study of the chromatographic retention of various trimethylsilylated silicic acids on different stationary phases Apiezon L and silicone OV-1 and OV-17. The analysis of metals in the form of volatile complexes continues to attract attention, and have been described for analysing sodium [412], potassium [412], radium [413], caesium [413], barium [414], calcium [414], strontium [415], beryllium [416, 417], magnesium [418], zinc [419, 420], nickel [419], mercury [421], copper [422, 423], silver [424, 425], cadmium [421], indium [426, 427], g ium [428], scandium [217], cobalt [421], thallium [426], hafnium [429, 430], lead [431, 432], titanium [430], vanadium [433], chromium [434-436], manganese [426], iron [437], yttrium [438], platinum [439,440], palladium [439, 441, 442], zirconium [430], molybdenum [443], ruthenium [444], rhodium [445], rare earths [446—449], thorium [221, 450, 451] and uranium [221, 452]. The literature on GC analysis of metal chelates was reviewed by Sokolov [458]. 

P 5l,95.2,iBa4BiO 2Tlo,9. 05. Barium bismuth lead thallium oxide (Ba4BiPbi95.2, Tlo.9.i,o50i2). [133494-87-8], 30 208 Pb2Cao,5Cu308Sr2Yo,5. Calcium copper lead strontium yttrium oxide (Cao.sCu3Pb2Sr2Yo.5O8). [118557-22-5], 30 197... 

Among the high-temperature superconductors one finds various cuprates (i.e., ternary oxides of copper and barium) having a layered structure of the perovskite type, as well as more complicated oxides on the basis of copper oxide which also include oxides of yttrium, calcium, strontium, bismuth, thallium, and/or other metals. Today, all these oxide systems are studied closely by a variety of specialists, including physicists, chemists, physical chemists, and theoreticians attempting to elucidate the essence of this phenomenon. Studies of electrochemical aspects contribute markedly to progress in HTSCs. 

Since the proteins contain negatively charged groups such as phosphates, side-chain carboxyls, terminal carboxyls, and sulfhydryls, they bind a number of different cations, such as calcium, barium, strontium, magnesium (Dickson and Perkins 1969), copper (Dill and Simmons 1970 Aulakh and Stine 1971), thallium (Sundararajan and Whitney 1969), potassium and sodium (Ho and Waugh 1965), iron (Basch et al. 1974, Demott and Park 1974 Demott and Dincer 1976), cadmium (Roh et al. 1976), and mercury (Roh et al. 1975). 

The ICP-AES as well as ICP-MS coupling technique give reliable analytical information at low detection levels. The ICP-AES technique was used for cadmium, copper, lead, and zinc assay in soil samples at ppm levels.106 The best reliability is assured by the laser-ICP-MS technique.107 It was successfully used for magnesium, aluminum, calcium, chromium, manganese, iron, cobalt, nickel, copper, zinc, strontium, cadmium, barium, thallium, lead, bismith, and uranium assay from soil samples, with a relative standard deviation less than 7%. For improving the reliability of the analytical information it is necessary to use an internal standard. It is not easy to use the laser-ICP-MS technique, but it gives the best results for metals assay in soil samples. 

The metals that are suitable as color producers in flames are mainly found in the first two columns of the periodic system—lithium (red), sodium (yellow), potassium (violet), rubidium (red), cesium (blue), calcium (orange-red), strontium (red), barium (green), radium (red), and copper (blue or green). To these might be added boron and thallium (both green) and the weak color producers zinc (bluish white), indium (pale blue), and tellurium (greenish). 

In his famous table of 1969, Mendeleev wrongly placed mercury with copper and silver, he misplaced lead with calcium, strontium, and barium, and he also misplaced thallium among the alkali metak. For a more detailed set of comparisons, see J. van Spronsen, The Periodic System of the Chemical Elements, the First One HundredYears, Elsevier, Amsterdam, 1969, pp. 127—131. The misplacement of mercury with silver is perhaps not altogether surprising given that hydrargyrum, the Latin name for mercury, means liquid silver. ... 

Bismuth chromates group Calcium chromates group Copper chromates group Iron chromates group Lead chromates group Zinc chromates group Barium chromate(VI) Barium potassium chromate Cadmium chromate Crocoite Manganese chromate Mercury chromate Silver chromate Strontium chromate Thallium chromate Tin chromate... 

Copper > Lead, Mercury > Nickel > Cobalt > Manganese > Barium > Strontium > Calcium > Silver > Thallium > Zinc > Lithium = no explosion... 

---