Bose-glass behavior of the vortex system in epitaxialBi2Sr2

Vortex dynamics in heavy-ion-irradiated single crystals ofBi2Sr2CaCu2O8+δandAmmor1, Hong2, Pignon3 et al. 2004Phys. Rev. B

“…25 Those exponents are also consistent with those reported for heavy-ion-irradiated Tl 2 Ba 2 CaCu 2 O 8 thin films. 31 In the BSCCO system, Miu et al 32 reported an average of the combined critical exponents n = Ќ ͑z −2͒ of 9 for BSCCO thin films irradiated at B = 1 T, while Seow et al 7 obtained n as of 8.5 from the c-axis resistivity measurements on BSCCO single crystals irradiated at B = 2 T. These two values are about 3 times larger than our results. The difference in critical exponents can be explained because columnar tracks are misaligned by 2°-3°in the previous studies on irradiated BSCCO single crystals (for an example, see Ref.…”

Influence of columnar defects on vortex dynamics inBi2Sr2CaSeow1, Campbell2, Paul3 et al. 1996Phys. Rev. BSelf Cite443211View full textAdd to dashboardCite

“…Further, the irreversibility field is already very large at 10 K so that it may not be surprising that only small enhancements in U may be achieved by increased disorder at this temperature. Miu et al 9 have also recently reported only a small enhancement ͑at tϭT/T c ϭ0.9͒ in U in BSCCO thin films after heavy ion irradiation. Our data is equally well reconciled with theirs taking into account the increased enhancement in U which they predict for lower temperatures.…”

“…It must be emphasized that there is considerable scatter in reported values for the glass exponent, both for vortex and Bose-glass phases. Budhani, Holstein, and Suenaga 17 obtained n values of ͑3.6-4.5͒Ϯ0.3 for Tl 2 Ba 2 CaCu 2 O 8 thin films irradiated at B ⌽ ϭ3.1 T, whereas Miu et al 9 reported an average n value of 9, for BϽB ⌽ at B ⌽ ϭ1 T from in-plane transport measurements of BSCCO thin films. On the other hand, Gammel, Schneemeyer, and Bishop 56 determined a vortex glass exponent v(zϪ1)ϭ6.5Ϯ1.5 for YBa 2 Cu 3 O 7Ϫ␦ single crystals, while Safar et al 57 have reported v(zϪ1)Ϸ7Ϯ1 for BSCCO crystals ͑from in-plane transport data͒.…”

“…Further evidence for the quasi-2D nature of BSCCO in the mixed state is related to observations that dissipation is determined only by the component of the field parallel to the c axis and is independent of the current direction. [2][3][4][5][6] On the other hand, there is much experimental evidence [7][8][9][10][11][12] to support the fact that pancake vortices pinned by columnar tracks in heavy-ion irradiated BSCCO crystals behave as well-coupled vortex lines at fields up to the matching field, B ⌽ . The pinning is strongest when the magnetic field is aligned or close to alignment with the columnar tracks.…”

“…These have either only been shown to fit moderately anisotropic materials like La 2Ϫx Sr x CuO 4 and YBa 2 Cu 3 O 7Ϫ␦ , or have had limited ranges of applicability. On the other hand, there is also some evidence to suggest that thermally activated flux flow ͑TAFF͒ induced dissipation also occurs in BSCCO films 2,9,35 and crystals, 36,37 even in the Lorentz force-free configuration. Moreover the possible effects of columnar disorder on this apparent Lorentz force-free dissipation have never been systematically investigated despite being an obvious critical test for such models.…”