Characterizing Coated Conductors with Variable Temperature Scanning Laser Microscopy (SLM)
Abstract
The grant supported research effort to understand factors limiting current-carrying capabilities in coated conductors (CCs). Three new operating modes of scanning laser microscopy (SLM) were developed under this grant, and total of five SLM modes were utilized for the research. The research found that the increased local-current density (current-crowding) was the main cause for the dissipation and the limiting factor for the current-carrying capacity. It was found in striated CCs that the current-crowding was caused by scratches from sample-handling, localized damages during striation process, or current flow configuration due to specific striation patterns. The other aspect of the research was to understand superconducting dissipation from various YBCO-family films on bicrystal grain boundary (GB) junctions. The samples on 240 [100]-tilt GB showed that the dissipation appeared like "hot-spots" along GB. There was no significant difference in the size and/or the pattern of hot-spots for different YBCO-family samples (regardless of nanoparticle additions, doping, and multi-layering) even though the current-carrying capability varied widely among the samples. The results implied that SLM features were determined by the GB angles not by the property of YBCO films when the dissipation began and the hot-spot appeared on GB.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 03, 2008
- Accession Number
- ADA492446
Entities
People
- Chuhee Kwon
Organizations
- California State University, Long Beach