Atomically flat MOD La0.7Sr0.3MnO3 buffer layers for high critical current YBa2Cu3O7 TFA films

Superconducting YBa2Cu3O7 (YBCO) thin films were grown by the trifluoroacetates route onto metallorganic deposited La0.7Sr0.3MnO3 (LSMO) buffer layers. The growth conditions of the LSMO films have been studied in detail and fully strained epitaxial layers with atomically flat surfaces have been obtained with local roughness similar to 1 nm, as determined by atomic force microscopy. We prove that this surface morphology is a key parameter for achieving YBCO/LSMO multilayers with high critical current densities in self- field, J(c)(sf) (77 K) = 1.8 MA cm(-2). Angular pinning studies demonstrate that the defect structure is modified with respect to standard TFA-YBCO films as a pronounced peak in J(c) is observed for H parallel to c at high temperatures. This indicates the presence of anisotropic defects playing an important role in vortex pinning even at the irreversibility line stressing the suitability of these all-chemical TFA-YBCO/LSMO multilayers as conductive coated conductor architectures.