Viscous flow in Al-doped YBCO high- Tc superconductor thick tapes

• Published in: Physica. B, Condensed matter Vol. 321; no. 1; pp. 368 - 374
• Main Author: Abu-Samreh, Mohammad M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2002; Elsevier
• Subjects: Applied sciences; Concentration; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cuprates superconductors (high tc and insulating parent compounds); Effects of crystal defects, doping and substitution; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; High-Tc compounds; Physics; Superconducting device characterization, design, and modeling; Superconductivity; Superconductors; Temperature; Transition temperature variations; Viscosity coefficient; Viscous; Y-based cuprates; Viscosity coefficient; Superconductors; Viscous; Temperature; Concentration; Viscosity; Critical current density; Temperature dependence; Inorganic compounds; Transition element compounds; Doping; Magnetic field effects; Silver additions; Experimental study; Flux pinning; Superconducting tapes; Barium oxides; Scaling laws; High-Tc superconductors; Flux-line lattices; Magnetic aftereffect; Quaternary compounds; Copper oxides; Yttrium oxides
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/S0921-4526(02)01077-3

The viscous flow in Al-doped YBCO laser-ablated thin films was studied on the basis of the flux-line lattice model. The viscosity coefficient was derived from the scaling laws of the pinning force, the current density, the magnetic field, and the resistivity. Dependence of the magnetic viscosity coefficient on temperature and Al concentrations has been reported for the temperature range from 75 to 95 K. The viscosity coefficient is found to have a significant non-linearity in its temperature dependence. It is almost independent of temperature at low temperatures, then exhibits a peak around the reduced temperature t=0.95 ( t= T/ T c). Above the reduced temperature (or above the transition temperature) it decreases rapidly as the temperature increases. This type of dependence is found to fit an empirical power law of the form (1− t) −1.12 for samples of different Al concentrations.