Effect of a multi-buffer layer (Sm2O3/CeO2) on the superconducting properties of an EuBa2Cu3O7−δ thin film

Abstract In order to suppress the influence of facets, annealing of a thick CeO 2 film and insertion of a Sm 2 O 3 buffer layer were carried out. Annealing of R-Al 2 O 3 with a 200-nm-thick CeO 2 buffer layer at 1000 °C for 3 h resulted in improvement in the surface morphology and crystallinity of the buffer layer. However, microcracks were observed on the surface of the CeO 2 film, and EuBa 2 Cu 3 O 7− δ (EBCO) thin films directly deposited on annealed substrates exhibited T ce ’s of about 84 K or lower. By depositing 100-nm-thick Sm 2 O 3 second buffer layers on annealed CeO 2 , EBCO thin films exhibited T ce ’s of 90.1 K and J c ’s of 5.5 MA/cm 2 at 77.3 K.