Abstract
High-temperature X-ray measurements were carreid out in the Bi-Sr-Ca-Cu-O system to investigate the partially melting states in which the high Tc phase (37 A phase) is produced by heat treatment. Two samples with 2212 and 4336 compositions were examined as the representatives of non-forming and forming the 37 A phase by heat treatment. respectively. The inconguruent melting was found to take place in both samples to give new crystalline phases coexisting with liquid phases. It was noted that the new crystalline phases of the two samples were different from each other. It is thus suggested that the crystalline phase of the 4336 sample reacts with the liquid and the 30 A phases in the partially melting state to produce the 37 A phase. In the cooling process. the 30 A phase was crystallized at the solidifying temperature and then the 24 A phase appeared at the lower temperature for both of the compositions.
