EARLY STAGES OF GROWTH OF YBA2CU3O7-DELTA HIGH-TC SUPERCONDUCTING FILMS ON (001) Y-ZRO2 SUBSTRATES

The early stages of growth of high quality YBa2Cu3O7-delta (YBCO) film s grown on (001) Y-ZrO2 (YSZ) substrates by pulsed laser deposition ha ve been studied using a combination of atomic force microscopy and tra nsmission electron microscopy. A one unit cell thick YBCO layer and re latively large CuO particles formed in the initial stages. Additional YBCO grew on top of the first layer in the form of one or a few unit c ell high c-axis oriented islands about 30 nm in diameter. The rounded islands subsequently coalesced into faceted domains. Elongated Y2BaCuO 5 particles nucleated after the first layer of YBCO. A highly textured BaZrO3 layer formed between the YSZ and the YBCO with a cube-on-cube dominant orientation relationship with respect to the YBCO film.