Direct observation of magnetic flux lattice melting and decomposition in the high-Tc superconductor Bi2.15Sr1.95CaCu2O8+x

First-order melting and dynamics of flux lines in a model forYBa2Cu3Ryu1, Stroud2 1996Phys. Rev. B432581View full textAdd to dashboardCite

“…Namely, even in clean YBa 2 Cu 3 O 7−δ , there are long lines of disclinations parallel to the c axis at relatively low fields (B < ∼ 10kG), but these break up into short ("2D") disclinations at higher fields. We believe that this breakup may be an essential ingredient in the "3D-2D" transition recently reported in BSCCO [6,32,33]. In clean systems, we find numerically that the distribution of defect line lengths is approximately exponential in the liquid, but deviates from exponential in the solid phase.…”

“…Much recent work on 3D flux-lattice melting transition has been stimulated by the behavior of high-T c materials [5][6][7]. Several experiments have convincingly demonstrated that the transition there is first-order in a sufficiently clean system at sufficiently low fields [8,9].…”

Growth of Bi-2212 single crystals and oxygen diffusion studies

“…If the oxygen diffusion would be in the c-direction, the relaxation time for sample B had to be 100 times larger than that of sample A. This is in contradiction with the experimental result, the relaxation time for sample B being only 6 times larger than that of (2) After subsitution of the values for a, b, and t ( the relaxation time is defined in Fig.4) , for sample A and B, we get a > 5-6 and Dab-~6.12xl0S(cmZ/s) at 500 ° C. It follows that the oxygen out-diffusion in the a-b plane is also quite anisotropic and it is mainly along the a-direction.…”

“…The "large volume" sample was a big crystal of approximately 12×5×1.5mm 3 which weighted 690mg. Neutron diffraction results showed that this 0921-4534/94/$07.00 © 1994 -Elsevier Science B.V. All rights SSDI 0921-4534(94)00827-2 sample actually consisted of one large aid one small single crystal which were closely aligned with their c-axis coinciding within 2" and with respective rocking curve widths of 0.4 ° , and 0.6" [2]. The "large-surface" sample for muon-spin rotation experiments was composed from 5 thin singlecrystalline pieces of typical size of 5 x5 ×0.5mm 3 with well-defined a-and b-directions, and the cdirection perpendicular to the surface [3].…”

SANS study of vortex lattice structural transition in optimally doped (Ba1−xKx)Fe2As2

“…They explained that the discrepancy may possibly arise from differences in sample purity and pinning [20]. In the high-T c superconductor Bi 2 Sr 2 CaCu 2 O 8+x the vortex lattice has been studied via SANS [21] with some other complementary technique such as Muonspin rotation and Hall-sensor arrays magnetometry by P. H. Kes and colleagues [18]. They reported that Muon-spin rotation and SANS experiments gave the first indications for an abrupt change of the vortex lattice structure along a line in the (B-T ) phase diagram.…”