Flux Pinning Mechanism in BaSnO3-Added GdBa2Cu3O7-x Films with Different Thickness

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

“…The shift of the maximum towards higher magnetic fields, according to [40], is associated with a change in the pinning mechanism during the introduction of BSO nanoinclusions, while the distinguishable dual-peak structure is possibly due to the presence of dual pinning mechanisms, operating simultaneously. A similar shift of the maximum toward higher magnetic fields was observed by Oh et al [33] in the reduced coordinates with normalized pinning force and normalized magnetic field.…”

“…Thus, we can state that, in contrast to [33,40], the pinning mechanism does not change in the YBCO films under study when the nanoinclusions of BSO or BZO are introduced. In our opinion, such a strong difference is mainly due to different methods of the thin film synthesis and different types of substrates.…”

“…To compare our data with [33] based on the Dew-Hughes scaling law [41], we normalized the pinning force by F p (max) and magnetic field by irreversibility field H irr (taken as 8 T) h = H/H irr . The resulting dependences F p /F p (max) vs h have pronounced dome-like shape for all three samples, and the maximum point did not shift with doping (figure 2(b)).…”

“…To gain insight into the nature of the influence of pinning nanoinclusions on the critical characteristics of HTSC, it is necessary to study their impact on the structure of a superconductor. There are several publications on the microstructure of REBCO composites with BaZrO 3 [21,26,27,[30][31][32] and BaSnO 3 [22,26,27,33]. Transmission electron microscopy [30] and x-ray diffraction (XRD) [21,31,32] are actively used for this purpose.…”

“…Prayoonphokkharat et al [22] found the secondary phase BaSnO 3 in tin-doped YBCO and proved using XANES spectroscopy that tin does not substitute for copper. Oh et al [33] reported the EXAFS study of GdBa 2 Cu 3 O 7−δ films with BaSnO 3 nanoinclusions fabricated using PLD. They concluded that the films have local oxygen deficiency at the apical position, depending on the film thickness and acting as additional pinning centers, which are most efficient for 0.8 µm thick films.…”