Abstract
It is known that the 124 phase Y-Ba-Cu-O superconductor is stabler on heating rather than that 123 phase. Many studies reported that 124 phase was formed in high pressure oxigen atomosphere. In order to form the phase at ordinary pressure, the alkali carbonate has been used as catalysts. So it has been difficult to prepare the long tape.
We succeeded in preparing the 124 phase Y-Ba-Cu-O superconducting thick film on Ag tape by pyrolysis of organic acid salts at ordinary pressure. The length of the tape was about 6m. The superconducting tape had 80K of Tc onset, 70K of Tc endpoint, and 2×104A/cm2 of Jc at 4.2K.
We confirmed the increases of Tc of Ca-substituted sample in the same process.
