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Direct observation of melting and solidification of Bi1.8Pb0.4Sr1.9Ca2.1Cu3.5Ox in various oxygen atmospheresby high temperature optical microscopy Lu, X. Y. Nagata, A. Sugawara, K. Kamada, S. Lu, Xiaoye Bi-superconductor Oxygen Melting Solidification Microstructure The melting and solidification processes of the Bi1.8Pb0.4Sr1.9Ca2.1Cu3.5Ox in various oxygen atmospheres have been observed in situ using a high temperature optical microscopy. In the melting process, the samples began to melt at 788℃ in N2, 862℃ in 8％O2+N2, 880℃ in air, 895℃ in O2. Many dark needle-like crystals (Sr,Ca)2CuO3 and the white bar-like crystals (Sr,Ca)CuO2 appeared in the liquid phase. When the temperature was raised, (Sr,Ca)CuO2 first melted and then (Sr,Ca)2CuO3 melted peritectically ((Sr,Ca)2CuO3 →CaO+L). In the solidification process, two peritectic reactions CaO+L→(Sr,Ca)2CuO3 and (Sr,Ca)2CuO3 + L→Bi-2212 were observed in the atmospheres of air, 8％O2+N2, and O2, whereas in N2, only a reaction of L→ Bi-2201 was observed. journal article Elsevier 2001-05-01 AM application/pdf Physica C 1-4 354 313 320 https://air.repo.nii.ac.jp/record/710/files/lu-air6.pdf http://hdl.handle.net/10295/440 https://air.repo.nii.ac.jp/records/710 eng https://doi.org/10.1016/S0921-4534(01)00099-5 open access