%0 Journal Article
%A Celentano, G.
%A Rizzo, F.
%A Augieri, A.
%A Mancini, A.
%A Pinto, V.
%A Rufoloni, A.
%A Vannozzi, A.
%A MacManus-Driscoll, J. L.
%A Feighan, J.
%A Kursumovic, A.
%A Meledin, A.
%A Mayer, J.
%A Van Tendeloo, G.
%T YBa 2 Cu 3 O 7−x films with Ba 2 Y(Nb,Ta)O 6 nanoinclusions for high-field applications
%J Superconductor science and technology
%V 33
%N 4
%@ 1361-6668
%C Bristol
%I IOP Publ.
%M FZJ-2020-02554
%P 044010 -
%D 2020
%X The structural and transport properties of YBa2Cu3O7−x films grown by pulsed laser deposition with mixed 2.5 mol% Ba2YTaO6 (BYTO) and 2.5 mol% Ba2YNbO6 (BYNO) double-perovskite secondary phases are investigated in an extended film growth rate, R = 0.02–1.8 nm s−1. The effect of R on the film microstructure analyzed by TEM techniques shows an evolution from sparse and straight to denser, thinner and splayed continuous columns, with mixed BYNO + BYTO (BYNTO) composition, as R increases from 0.02 nm s−1 to 1.2 nm s−1. This microstructure results in very efficient flux pinning at 77 K, leading to a remarkable improvement in the critical current density (Jc) behaviour, with the maximum pinning force density Fp(Max) = 13.5 GN m−3 and the irreversibility field in excess of 11 T. In this range, the magnetic field values at which the Fp is maximized varies from 1 T to 5 T, being related to the BYNTO columnar density. The film deposited when R = 0.3 nm s−1 exhibits the best performances over the whole temperature and magnetic field ranges, achieving Fp(Max) = 900 GN m−3 at 10 K and 12 T. At higher rates, R > 1.2 nm s−1, BYNTO columns show a meandering nature and are prone to form short nanorods. In addition, in the YBCO film matrix a more disordered structure with a high density of short stacking faults is observed. From the analysis of the Fp(H, T) curves it emerges that in films deposited at the high R limit, the vortex pinning is no longer dominated by BYNTO columnar defects, but by a new mechanism showing the typical temperature scaling law. Even though this microstructure produces a limited improvement at 77 K, it exhibits a strong Jc improvement at lower temperature with Fp = 700 GN m−3 at 10 K, 12 T and 900 GN m−3 at 4.2 K, 18 T.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000525650500001
%R 10.1088/1361-6668/ab6ee5
%U https://juser.fz-juelich.de/record/877980