Effect of annealing conditions on the electrical properties of screen printed Y-Ba-Cu-O thick films

Özet

The electrical properties of $YBa_2Cu_3O_{7-x}$ screen-printed thick films on MgO(100), sapphire and alumina substrates were investigated as a function of annealing temperature. Temperature variation of resistivities were found to depend on annealing conditions. For films on Ag/sapphire and Ag/alumina substrates, the best value of calcination temperature and duration were found to be 890 $\pm$ 10° C, 15 min. Above this temperature, resistivities increased probably due to film-substrate interaction, thus superconductor phase ratio and Tc{R = 0) decreased and AT(10%, 90%) increased. For the films prepared on bare MgO substrates, the calcination temperature interval was found to be 870-930 ° C, which is larger than the calcination temperature interval for films on other substrates. X-ray diffraction and SEM studies indicated that the films had no preferred orientation. The best superconducting thick film with Tc{R = 0) = 82 K and Jc(77K) = 2 A/cm2 was obtained on MgO.