Barium calcium copper thallium oxide

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. 

Ba2CaCu20gTl2. Barium calcium copper thallium oxide (Ba2CaCu2Tl20g). (115833-27-7], 30 203... 

Ba2Ca2Cu30ioTl2, Barium calcium copper thallium oxide (Ba2Ca2Cu3Tl20 o). (115866-07-4), 30 203 Ba2CuO Tl2, Barium copper thallium oxide (Ba2CuTl206), (115866-06-3], 30 202... 

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

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. 

Hydrogen sulfide is rapidly oxidised, and may ignite in contact with a range of metal oxides, including barium peroxide, chromium trioxide, copper oxide, lead dioxide, manganese dioxide, nickel oxide, silver(I) oxide, silver(II) oxide, sodium peroxide, and thallium(III) oxide. In the presence of air, contact with mixtures of calcium oxide or barium oxide with mercury oxide or nickel oxide may cause vivid incandescence or explosion. 

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... 

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