Critical current and texture relationships in YBa2Cu3O7 thin films

Preferred orientation and the microstructure of polycrystalline YBa2Cu3O7 films, both of which strongly depend on the substrate used, have been shown to be important factors in determining the critical current density. A film grown on cubic ZrO2 has a random polycrystalline structure with a Jc of 2.4×104A/cm2 at 5K. In contrast, a film with a [001] texture (grown on BaF2) has significantly higher Jc of 7.47×104A/cm2. The characteristic differences in the temperature dependence of Jc in these two types of films are discussed.