DECOMPOSITION PRODUCTS OF SUPERCONDUCTING (BI,PB)2SR2CA2CU3O10+DELTA

High-temperature in situ x-fay studies of Pb-doped Bi2Sf2Ca2Cu3O10+delta have been carried out in a variety of different environments in order to determine the range of stability and the decomposition products that appear as this material transforms into other phases. In air at 840-degrees-C, a combination of Bi2Sr2Ca0Cu1O6+delta, Ca2PbO4, (Sr,Ca)2Cu1O3, and some liquid phase coexists with Bi2Sr2Ca2Cu3O10+delta as it gradually decomposes. When the Bi2Sr2Ca2Cu3O10+delta is completely gone, the Bi2Sr2Ca0Cu1O6+delta, Ca2PbO4, and (SrCa)2Cu1O3 transform to a liquid with CaO and other phases floating on the liquid. If Ag is micromilled with the Bi2Sr2Ca2Cu3O10+delta, the decomposition process is similar, but all of the temperatures are lowered substantially. If the partial pressure of O2 is reduced to 10 kPa over the B2Sr2Ca2Cu3O10+delta/Ag sample, the decomposition temperatures and products are similar to the 20 kPa case.