Flux pinning in YBa2Cu3O7 thin films grown by d.c. magnetron sputtering

Strong flux pinning in YBa2Cu3O7−δthin films due to nanometer-sized precipitates

“…The flux pinning mechanisms of epitaxial YBa 2 Cu 3 O 7−δ (YBCO) thin films have been extensively studied because high-quality YBCO films show much higher critical current densities J c (>10 GA m −2 at 77 K) than other grain-oriented YBCO specimens such as single crystals or melt-textured bulk materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. To explain such high J c in YBCO thin films, Hylton and Beasley proposed that the pinning is due to a large density of point defects in the CuO 2 planes, based on a simple theoretical model [1].…”

Flux-pinning mechanisms in high current density superconducting YBa₂Cu₃O₇ films

“…So far many studies have been made on the flux-pinning mechanisms of epitaxial (RE)Ba 2 Cu 3 0 7 thin films (RE = Y, Nd, Sm, Gd, Dy, Ho, ---; abbreviated as (RE)BCO), in which high Je values have been observed [1][2][3][4][5][6][7][8][9]. In early days Hylton and Beasley theoretically pointed out that high J 0 observed in YBCO thin films is due to high density of point defects [1].…”

“…In early days Hylton and Beasley theoretically pointed out that high J 0 observed in YBCO thin films is due to high density of point defects [1]. There were several experimental studies reporting that Jc of YBCO films increased with the density of nanometer-sized Y 2 0 3 precipitates and that they are effective pinning centers [2,3]. As extended defects 77 correlated along the c-axis of YBCO, screw dislocations formed with the crystal growth of YBCO and twin boundaries that exist in all the superconducting (orthorhombic) YBCO films were sometimes claimed to be primary pinning centers [4][5][6], but such claims were not supported because there was not good correlation between Jc and defect density.…”

Flux-pinning mechanisms in high current density superconducting YBa₂Cu₃O₇ films

“…In early days Hylton and Beasley theoretically pointed out that high J c observed in YBCO thin films is due to high density of point defects [1]. There were several experimental studies reporting that J c of YBCO films increased with the density of nanometer-sized Y 2 O 3 precipitates and that they are effective pinning centers [2,3]. As extended defects correlated along the c-axis of YBCO, screw dislocations formed with the crystal growth of YBCO and twin boundaries that exist in all the superconducting (orthorhombic) YBCO films were sometimes claimed to be primary pinning centers [4][5][6], but such claims were not supported because there was not good correlation between J c and defect density.…”

“…So far many studies have been made on the flux-pinning mechanisms of epitaxial (RE)Ba 2 Cu 3 O 7 thin films (RE = Y, Nd, Sm, Gd, Dy, Ho, ---; abbreviated as (RE)BCO), in which high J c values have been observed [1][2][3][4][5][6][7][8][9]. In early days Hylton and Beasley theoretically pointed out that high J c observed in YBCO thin films is due to high density of point defects [1].…”