Effect of high pressure on the electrical resistivity of optimally doped YBa2Cu3O7− single crystals with unidirectional planar defects

Effect of high pressure on the fluctuation paraconductivity in Y0.95Pr0.05Ba2Cu3O7−δ single crystals

“…(5) grows from 1.46 to 1.65 Å with increasing T c . This is qualitatively different from the analogous pressure dependences of x c (0) for substituent-free YBCO samples [4], for both optimally doped [19,22] as well as underdoped single crystals [20]. As it was revealed in Ref.…”

“…This rate is slightly less than in compounds with x ! 0.1, but greater than in substituent-free YBa 2 Cu 3 O 7Àd single crystals [21,22]. In Fig.…”

“…Thus, in the case of substituent-free samples it is often necessary to employ specific techniques to distinguish between the "true pressure effect" [21,22], that is caused by the changes in the crystal lattice, interlayer interaction, electronephonon interaction and so forth, and the relaxation effect [17,18] due to the redistribution of the labile component. Despite rather numerous reports on the investigation of the effect of pressure on the conductivity in HTSC cuprates, only a minor portion of these has been devoted to the study of the pressure dependences of the resistive characteristics of Y 1Àx Pr x Ba 2 Cu 3 O 7Àd compounds, see Ref.…”

Modification by high pressure of fluctuation paraconductivity of underdoped HoBa2Cu3O7-δ single crystals

“…It should be noted that the value of the transverse coherence length changes not only in the case of the direct application of high pressure (the so-called ''true'' pressure effect [58,59])-Sects. 1 and 2, but also during the isobaric exposure of the sample at a fixed pressure at room temperature for 1 week-Sects.…”

Effect of electron irradiation on the fluctuation conductivity in YBa2Cu3O7−δ single crystals

“…During the transition through the 2D-3D crossover point, these curves can be well described in the framework of the Lorentz-Doniach model [15] or Maki-Thompson process [16], depending on the degree of perfection of each particular experimental sample [17]. High pressure [13,18], high-temperature annealing [19], along with long-term aging processes [20], can substantially shift the 3D crossover point, and also lead to phase separation [14] as a result of the structural relaxation induced by these extreme conditions. The magnetic field, as a rule, leads to a significant blurring of the superconducting transition [21,22] due to the appearance of specific dynamic transitions in the SC subsystem.…”