Thermal Fluctuations of (Tl0.5Pb0.5)Sr2(Ca0.9Gd0.1)Cu2Oz Bulk Superconductor |
| W.M. Wocha, M. Chrobaka, A. Kołodziejczyka and G. Gritznerb
aSolid State Physics Department, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Kraków, Poland bInstitute for Chemical Technology of Inorganic Materials, Johannes Kepler University, A-4040 Linz, Austria |
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| We report on the critical fluctuations from the magnetoresistance measurements in polycrystalline (Tl0.5Pb0.5)Sr2(Ca0.9Gd0.1)Cu2Oz superconductor. The critical exponents have been calculated above the critical temperature Tc as well as in the temperatures interval close to the zero resistance critical temperature. Above Tc only Gaussian fluctuations have been observed in a three-dimensional fluctuating system. Additionally, far above Tc the applied magnetic field induces the crossover from 3D to 2D fluctuating system. At the temperatures range close to the zero critical temperature the properties of the weak links are dominating and the fluctuating phase in each grain becomes long-range ordered as a consequence of the activation of weak links between grains. |
| DOI: 10.12693/APhysPolA.121.1059 PACS numbers: 74.72.-h, 74.40.-n, 74.20.De, 74.25.Ha |