The influence of hydrostatic pressure up to 0.48 GPa on the fluctuation conductivity σ′(T) and pseudogap (PG) Δ∗(T) of slightly doped HoBa2Cu3O7-δ single crystals with Tc≈ 62 K and δ≈0.35 is studied with current passing under an angle 45° to the twin boundaries. It is shown that near Tc the conductivity σ′(T) is well described by the Aslamasov–Larkin and Hikami–Larkin fluctuation theories demonstrating 3D–2D crossover with the increase of temperature. Δ∗(T) displays two representative maxima at View the MathML source and View the MathML source likely caused by the phase stratification of the single crystal. Pressure leads to disappearance of these maxima and linear Δ∗(T) with a positive gradient at high temperatures. Essentially, with the removal of pressure the maxima are restored. The comparison of our results with those obtained for YBa2Cu3O7-δ sheds more light on the role of magnetic subsystem in the high-Tc superconductors.
Bibliographical noteNOTICE: this is the author’s version of a work that was accepted for publication in Physica C: Superconductivity. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physica C: Superconductivity [Vol 501 (2014)] DOI: 10.1016/j.physc.2014.03.004 . © 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
- Fluctuation conductivity
- Single crystals
- Twin boundaries