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arXiv · 1004.1022

Vortex phase diagram and temperature-dependent second-peak effect in overdoped Bi$_{2}$Sr$_{2}$CuO$_{6 + \delta}$ crystals

Alexandre Piriou·Enrico Giannini·Yanina Fasano·Carmine Senatore·Øystein Fischer
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Abstract

We study the vortex phase diagram of the single-layer Bi2Sr2CuO6+d (Bi2201) superconductor by means of bulk magnetization measurements on high-quality oxygen-overdoped crystals. In striking contrast with the results found in the moderately-doped two and three-layer Bi-based cuprates, Bi2201 exhibits a strong temperature-dependent second-peak effect. By means of measurements of the in and out-of-plane first-penetration field we provide direct evidence that this phenomenon is mainly associated to an increase of the electromagnetic anisotropy on warming. The effect of oxygen-doping d on the vortex phase diagram results in both the irreversibility and second-peak lines shifting to higher temperatures and fields. This enhanced stability of the Bragg glass phase suggests that the interlayer coupling between Cu-O layers increases with d. In addition, we found that the critical temperature follows the parabolic relation with the number of holes per Cu-O plane that holds for most single and two-layer cuprates.

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Alexandre Piriou, Enrico Giannini, Yanina Fasano, Carmine Senatore, Øystein Fischer. 2010-04-07. Vortex phase diagram and temperature-dependent second-peak effect in overdoped Bi$_{2}$Sr$_{2}$CuO$_{6 + \delta}$ crystals. https://doi.org/10.1103/physrevb.81.144517

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