The influence of BaSnO₃ and BaZrO₃ nanoinclusions on the critical current and local structure of HTS coated conductors

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 YBa2Cu3O7−δ 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 HTSC - tapes.

Увеличение Критического Тока Сверхпроводящих Композитов При Имплантации Ионов Железа

“…В частности, в работах [12,13] было показано, что наночастицы BaZrO 3 имеют высокие перспективы как кандидаты в инертные центры пиннинга. Исследования по созданию искусственных центров пиннинга на основе нанодобавок проводились для ВТСП-пленок, полученных различными методами: импульсного лазерного напыления [14,15,16], металлоорганического осаждения жидких прекурсоров [17,18], осаждения металлорганических соединений из газообразной фазы [10,11,[19][20][21][22][23]. Наряду с монодобавками, рассматривался способ создания структур с комбинацией точечных и колончатых дефектов [24].…”

An increase in the critical current of superconducting composites upon implantation of iron ions

“…In particular, in [12,13] it was shown that nanoparticles of BaZrO 3 are very promising as candidates for inert centers of pinning. Investigations focused on the creation of artificial centers of pinning based on nanoadditives were carried out for HTS tapes produced by different methods: pulsed laser deposition [14][15][16], liquid delivery metal-organic precursors for the chemical vapor deposition [17,18], metal-organic compounds for the chemical vapor deposition [10,11,[19][20][21][22][23]. Along with monoadditives, a method of structure creation with a combination of point and columnar defects was considered [24].…”