In situ observation of oxygen absorption and desorption during heating and cooling cycle with TG and DTA was done to determine the optimum preparation conditions of high Tc Y-Ba-Cu-O compounds. We suggest the best recipe in air is to fire the raw mixture of 1/2Y2O3, 2BaCO3 and 3CuO at 930°C for more than 10 h, followed by slow cooling in the furnace to take as much oxygen as possible within the specimen. With this method single phase material of an orthorhombic superconducting oxide YBa2Cu3O6.74 with Tc=91.3 K was synthesized, with orthorhombic unit cell dimensions of a=3.8180(6) Å, b=3.8888(7) Å, and c=11.668(2) Å.
ASJC Scopus subject areas
- Physics and Astronomy(all)