ACTA

Magnetization, Susceptibility and Critical Currents of (Tl_2-xRe_x)Ba₂CaCu₂O_y Thin Films

W.M. Woch^a, A. Dujavová^b, J. Przewoźnik^a, R. Zalecki^a, A. Kołodziejczyk^a, M. Sojková^b and Š. Chromik^b
^aSolid State Physics Department, AGH University of Science and Technology, Mickiewicza 30, 30-059, Kraków, Poland
^bInstitute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 01 Bratislava, Slovak Republic

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The magnetization and the AC susceptibility vs. the temperature as well as the applied magnetic field of the thin film (Tl_2-xRe_x)Ba₂CaCu₂O_y with x=0 and 0.15 on R-plane sapphire substrate with CeO₂ buffer layer were measured and analyzed. XRD measurements show c-axis as well as a-b plane oriented Tl-1212 and superconducting pure phase. The zero critical temperature of the Tl-Re sample is 99.9 K and is practically the same as the critical temperature of the rhenium free sample: 99.5 K. The Tl-Re superconductor exhibits two peaks of the absorption part of AC susceptibility in the vicinity of the critical temperature in contrary to the rhenium free sample. The first peak placed in higher temperature is related to intragranular properties while the second peak is connected with the intergranular one. The critical current densities versus temperature were calculated from AC susceptibility as well as from the magnetization loops measurements using the Bean's critical state model. The Tl-Re film exhibits the higher critical current in comparison to the rhenium free thallium based film.

DOI: 10.12693/APhysPolA.121.845
PACS numbers: 70.72Gr, 74.25Ha