Low Temperature Physics: 36, 115 (2010); https://doi.org/10.1063/1.3292281 (4 pages)
Fizika Nizkikh Temperatur: Volume 36, Number 1 (January 2010), p. 143-147    ( to contents , go back )

Magnetoresistance and 2D-3D crossover in aluminium-doped YBa2Cu3-zAlzO7-d single crystals with the system of unidirectional twin boundaries

A.A. Zavgorodniy, R.V. Vovk, M.A. Obolenskii, and A.V. Samoylov

V.N. Karazin Kharkov National University, 4 Svobody Sq., Kharkov 61077, Ukraine
E-mail: Ruslan.V.Vovk@univer.kharkov.ua
pos Анотація:

Received August 4, 2009

Abstract

The effect of permanent magnetic field up to 12.7 kOe on temperature dependences of conductivity of aluminium-doped YBaCuO single crystals with the system of unidirectional twin boundaries is investigated. In the basal ab-plane the temperature dependences excess paraconductivity and the field dependence of coherent length xс(0,Н) along the c axis are obtained. It is shown that the twin boundaries are the effective scattering centers of fluctuation carriers. The temperature dependences of excess paraconductivity is interpreted in ternis of the Hikami–Larkin theoretical model for layered superconductivity systems. The reasons for suppression of three-dimensional superconductivity fluctuations and nonmonotonic dependence xс(0,Н) in weak magnetic fields directed along the axis c are discussed.

PACS: 74.25.F– Transport properties;
PACS: 74.40.–n Fluctuation phenomena;
PACS: 74.72.–h Cuprate superconductors.

Key words: fluctuation conductivity, YBa2Cu3O7-d single crystals, dope, twin boundaries, crossover, coherent length.

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