Optimization of the Superconducting Properties of Laser Ablated YBa2Cu3O7-δ Films on CeO2-Buffered Sapphire |
| I. Abal'osheva, I. Zaytseva, M. Aleszkiewicz, Y. Syryanyy, P. Gierłowski, O. Abal'oshev, V. Bezusyy and M.Z. Cieplak
Polish Academy of Sciences, Institute of Physics, al. Lotników 32, 02-668 Warszawa, Poland |
| Full Text PDF |
| We use pulsed laser deposition to grow YBa2Cu3O7-δ (YBCO) superconducting films for microwave applications. The films are grown on R-cut sapphire substrates, with CeO2 buffer layers, which are re-crystallized at high temperature prior to YBCO growth. Using the atomic force microscopy (AFM) and X-ray diffractometry we determine the optimal temperature for recrystallization (1000°C) and the optimal buffer layer thickness (30 nm). The properties of YBCO films of various thickness, grown on the optimized CeO2 buffer layers, are studied using several methods, including AFM, magnetooptical imaging, and transport experiments. The YBCO film roughness is found to increase with the increasing film thickness, but the magnetic flux penetration in the superconducting state remains homogeneous. The superconducting parameters (the critical temperature and the critical current density) are somewhat lower than the similar parameters for YBCO films deposited on mono-crystalline substrates. |
| DOI: 10.12693/APhysPolA.121.805 PACS numbers: 74.78.-w, 77.55.Px, 81.15.Fg |