Improved critical current densities in thick YBa2Cu3O7 − δ multilayer films interspaced with non-superconducting YBa2Cu3Ox nanodots

We have fabricated and studied quasi-multilayered thick YBa2Cu3O7 − δ (YBCO) films composed of several YBCO layers interspaced with quasi-layers of non-superconducting YBa2Cu3Ox nanodots, grown by Pulsed Laser Deposition on SrTiO3 (100) substrates. Magnetization Jc(B) at 77.3 K for these thick films showed significant improvement as compared to pure YBa2Cu3O7 − δ films of same or even smaller thickness. A high Jc(B) in our quite thick films (1 μm to 6 μm) provides a very high total critical current per centimetre of the film width, Ic − w. Critical current as high as 830 A per cm width in self field and 77.3 K was achieved in 5 μm thick quasi-multilayer film with non-superconducting YBa2Cu3Ox nanodots. Frequency-dependent susceptibility measurements showed also an increase in the pinning potential. The angular dependence of Ic − w at 86.5 K, in 3 T shows a clear indication of anisotropic pinning centres aligned along the c-direction.