Formation of Self-Assembled, Double-Perovskite, Ba₂YNbO₆Nanocolumns and Their Contribution to Flux-Pinning andJ_cin Nb-Doped YBa₂Cu₃O_7-δFilms

Abstract

Ba2RENbO6 (RE = rare earth elements including Y) compounds are considered new additives for superior flux-pinning in YBa2Cu3O7-δ (YBCO) films due to their excellent chemical inertness to and large lattice mismatches with YBCO. Simultaneous laser ablation of a YBCO target and a Nb metal foil attached to the surface of the target resulted in epitaxial growth of YBCO films having columnar defects comprised of self-aligned Ba2YNbO6 (BYNO) nanorods parallel to the c-axis of the film. Compared to pure YBCO, YBCO+BYNO films exhibited no Tc reduction as well as superior Jc performance with higher self- and in-field Jc by a factor of 1.5–7 and also exhibited a strong Jc peak for H∥c indicative of strong c-axis correlated flux-pinning.

Formation of stacking faults and their correlation with flux pinning and critical current density in Sm-doped YBa2Cu3OWee1, Specht2, Cantoni3 et al. 2011Phys. Rev. BSelf Cite

“…[1][2][3][4][5][6] In particular, epitaxial growth of self-organized, non-superconducting nanoscale defects aligned parallel to the c-axis of the film has resulted in strongly improved pinning and enhanced J c , particularly for the case where the magnetic field is also aligned parallel to the c-axis, H║c. [4][5][6] In addition to the incorporation of nanoscale defects, rare-earth (RE) element substitution in YBCO has been considered a complementary method for synergistic enhancement of flux-pinning. In fact, REBa 2 Cu 3 O 7-δ (REBCO) superconductors especially those with RE = Nd, Sm, Eu, and…”

High critical currents in heavily doped (Gd,Y)Ba2Cu3Ox superconductor tapes

“…[3][4][5][6][7] High critical current densities are being pursued in REBCO superconducting tapes in high magnetic fields (2-30 T) in a temperature range of 4.2 K-50 K for use of these materials in electric power applications such as motors, generators, superconducting magnetic energy storage (SMES) as well as in high energy particle accelerators, magnetic resonance imaging, and high-field magnets. Introduction of Y 2 BaCuO 5 , 8 BaZrO 3 (BZO), [9][10][11][12][13] BaSnO 3 ,14,15 BaHfO 3 , 16 Ba 2 YNbO 6 , 17,18 and Gd 3 TaO 7 19 nanoscale defects in the REBCO films of the superconducting tapes has been proven to be a powerful method to increase critical current density (J c ) of these tapes via enhanced flux pinning by these defects. Until recently, high J c in REBCO films with BaMO 3 (M ¼ Zr, Sn, and Hf) nanoscale defects has been obtained only with less than 10 mol.…”

Structural transition of secondary phase oxide nanorods in epitaxial YBa2Cu3O7−δfilms on vicinal substrates

“…In particular, extensive efforts have been made recently to generate secondary phase columnar nanostructures in HTS YBa 2 Cu 3 O 7À (YBCO) films to improve magnetic vortex pinning and hence to optimize the superconducting critical current (J c ) in magnetic fields. The doping of insulating impurities such as BaZrO 3 (BZO), BaSnO 3 (BSO), YBa 2 NbO 6 , and rare-earth tantalates have been identified as promising schemes for this purpose [2,3,[5][6][7][8]. While extended columnar defects provide an increased pinning force in superconducting films as they effectively pin magnetic vortices along their length, a splay alignment of the columnar defects has been found to reduce the possibility of vortex hopping, resulting in stronger pinning in high magnetic fields [9][10][11][12].…”