Strombegrenzende Mechanismen YBa2Cu3O7-[delta]-Dünnschichten und -Quasimultilagen

In this work, electrical transport properties and the maximum current carrying capability of YBa2Cu3O7-[delta] thin films and so called quasi-multilayers are investigated. These samples are prepared with pulsed laser deposition on single-crystalline substrates (SrTiO3) as well as on biaxially textured Ni tapes. The critical current density of coated conductors is limited by small-angle grain boundaries in low magnetic fields, but by the intra-grain pinning properties in higher magnetic fields. Accordingly, these investigations are divided into two parts: In the first part, the limitation of the critical current density by grain-boundaries and grain boundary networks is investigated with the main focus on the influence of geometrical factors such as the conductor width or the grain aspect ratio. In the second part, a possible enhancement of the critical current density due to different doping types (atomar doping using Zn and precipitate doping using BaMO3 where M is a transition metal) will be discussed. Here, not only the irreversibility field but also the pinning behaviour in very low magnetic fields is of interest to better understand the pinning mechanism of thin films.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Technische Universität Dresden

Year

2005

Author dc:creator

• Hänisch, Jens

Contributors dc:contributor

• Holzapfel, Bernhard
• Schultz, Ludwig
• Wosnitza, Joachim
• Mönter, Burckhard

• Bandleiter
• Korngrenzen
• Pinning
• Supraleitung
• YBCO
• coated conductors
• grain boundaries
• superconductivity