Magnetoresistance of Superconducting Granules and Grain Boundaries in Ceramic YBa2Cu3O7−δ High-Temperature Superconductors in Weak Magnetic Fields

Original Paper


The objective of the work is to establish the contribution of superconductive granules and grain boundaries (weak links) in magnetoresistance ρ value of YBa2Cu3O7−δ granular high-temperature superconductor (HTS) at T<T c. The current-voltage characteristics (CVCs) \(E(j)_{H_{\mathrm{ext}} = \mathrm{const}}\) of YBa2Cu3O6.95 ceramic samples were measured in H ext (0≤H ext≤≈500 Oe) magnetic fields. The CVCs \(E(j)_{H_{\mathrm{trap}} = \mathrm{const}}\) of the samples magnetized in H treat magnetic fields were measured at H ext=0. Based on the CVCs, \(\rho(j)_{H_{\mathrm{ext}} = \mathrm{const}}\), ρ(H ext) j=const and \(\rho(j)_{H_{\mathrm{treat}} = \mathrm{const}}\) dependences were reestablished. The comparative analysis of \(\rho(j)_{H_{\mathrm{ext}} = \mathrm{const}}\) and ρ(H ext) j=const dependences indicates the magnetic field redistribution between grain boundaries and superconductive granules influence on transport and galvanomagnetic properties of granular HTS. The superconductive grain magnetoresistance ρ g was established to be significantly lower than ρ J value of Josephson medium.


Granular HTS YBa2Cu3O7−δ Magnetoresistivity Current-voltage characteristic (CVC) 



The work was carried out under support of the Science and Technology Center in Ukraine (STCU Project # P424).


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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  1. 1.National Science Center “Kharkov Institute of Physics and Technology”KharkovUkraine

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