Magnetic-flux distribution and the magnetic penetration depth in superconducting polycrystallineBi2Sr2

Abstract

Results on the systematics of the magnetic penetration depth k,b in the high-temperature superconductors Bi2Sr~Cal, Y,Cu208+g (z =0,0.1,0.2,0.3,0.4, 0.45) and Bi2 Pb Sr2CaCu208+g(x=0.15,0.30,0.70) are reported from muon-spin-rotation measurements on polycrystalline samples with known oxygen excess 5. In determining A, ,z various additional sources for inhomogeneous internal field distributions, besides the one arising from the Aux-line lattice, have been critically taken into account. The most important one arises from a type of powder broadening due to the anisotropy of the field-cooled magnetization.

Using μSR to investigate the vortex lattice in high-temperature superconductors

“…1 [4]. Probability distributions similar to those shown have been observed in single crystals of high-Tr superconductors both by NMR and ~tSR [5][6][7][8].…”

“…1, however, ir is clear that the field distribution is in general by no means Gaussian, raising doubts as to the validity of this approach. In polycrystalline samples of HTSC the lineshapes are often in fact roughly Gaussian, due to the effects of averaging over orientations of differing demagnetization factors [6]. A study of powder samples in [10] showed that experimentally cr and (AB2) 1/2 are proportional, so for studying systematic trends cr provides a good relative measure of the penetration depth [11].…”

Pb0.4Bi1.6Ma1, Alméras2, Kelley3 et al. 1995Phys. Rev. B

“…[29] It is generally believed that Pb-doping does not perturb the electronic state critical to forming the superconducting state in this system. [31].…”

“…It was then found that the lead substitution has a strong influence on the incommensurate modulation that exists in the b−axis. [24][25][26][27][28][29] in both Bi−2212 and Bi−2223.…”

Magnetic penetration depth inRbOs2O6studied by muon spin rotation

“…[22,23]. All the µSR spectra taken at T < 0.85T c where the three lines are resolved were analyzed by fitting a three component expression to the P (t) data:…”