Flux pinning by a-axis grains in c-axis-oriented Y-Ba-Cu-O films

Abstract

We have investigated the relationship between the microstructures and pinning forces by measuring the magnetic-field dependence and angular dependence of Jc in several kinds of YBCO thin films having different microstructures. A high-Jc value was kept even when the magnetic field was applied perpendicular to the film plane in the case of a c-axis-oriented film which was studded with a-axis-oriented grains. The boundaries between the a-axis-oriented grain and the c-axis-oriented grain are considered to be effective as pinning centers.

The qualitative change in decomposition ofc-oriented Sm-123 films due to a minor change in substitution ofa-oriented grains

“…Figure 3(a) shows the SEM image of a section of film A: the irregular dots on the film are Ba-Cu-O impurities. Those needle-like objects on the flat area indicated by arrows are the so-called a-axis-oriented SmBCO grains, in which the long axis of a-axis-oriented grains runs along [1 0 0] or [0 1 0], while the short axis is [0 0 1]-oriented [17,18]. For film B, shown in figure 3(b), we observe that the portion of the a-axisoriented grains is higher than in film A.…”

Peritectic melting of thin films, superheating and applications in growth of REBCO superconductors

“…Those needle-like objects on the flat area indicated by arrows are so-called a-axis-oriented SmBCO grains. The long axis of those grains runs along h1 0 0i or h0 1 0i, while the short axis is h0 0 1i-oriented [37,38]. We can observe that the portion of the a-axis-oriented grains in film B ( Fig.…”

AC Losses in High-TC Superconductors with Finite Thickness

“…[9] and [10], the function h can be constructed using ) (q f and ) (q g as follows: (6) Since the mass of a pancake vortex is negligible, the corresponding term in Eq. [9] and [10], the function h can be constructed using ) (q f and ) (q g as follows: (6) Since the mass of a pancake vortex is negligible, the corresponding term in Eq.…”