Abstract: We studied the effect of artificial pinning centers in the form of nanoinclusions of stannate BaSnO3 (BSO) and zirconate BaZrO3 (BZO) barium on the critical current of high-temperature superconducting tapes of the second generation (2G) based on YBa2Cu3O 7-d films (YBCO). It has been found that the introduction of BaZrO3 nanoinclusions increases the critical current at 77 K for the magnetic field direction parallel and normal to the tape surface, while the introduction of BaSnO3 nanoinclusions decreases the critical current in both cases. To elucidate the origin of a different impact of nanoinclusions we examined the local structure of the YBCO-matrix using x-ray absorption spectroscopy (EXAFS and XANES). The spectra were collected at K-edges of Cu, Sn, and Zr at the European Synchrotron (ESRF). It was revealed that the introduction of BaZrO3 nanoinclusions increases the stiffness of copper-oxygen bonds in superconducting CuO2 plane and minimizes their static disorder in the YBCO matrix, while the introduction of BaSnO3 nanoinclusions leads to a significant increase in static disorder with a relatively weak effect on the stiffness of Cu-O bonds. These changes in the local structure become decisive for changing the macroscopic properties of high-temperature superconductor-tapes.

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