DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Comparative Study between Similarly Processed YBa2Cu3O7-x Films with Y2BaCuO5 or BaSnO3 Additions (Postprint)
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIR/POWER DIV/MECHANICAL ENERGY CONVERSION BRANCH
Pagination or Media Count:
A special YBa2Cu3O7-x YBCO target with a thin sector of second phase material, in this case either Y2BaCuO5 Y211 or BaSnO3 BSO, was used to deposit YBCO films with non-layered nanoparticles on single crystal LaAlO3 and biaxially textured Ni-5 at. W substrates buffered with CeO2 and YSZ layers coated conductors. Although identical processing conditions were used, TEM images indicated that random Y211 nanoparticles in the case of YBCOY211, and evenly spaced BSO nanocolumns in the case of YBCOBSO, form in the YBCO films. While YBCO plane buckling was observed at many places in the case of YBCOY211, a high density of stacking faults and dislocations were observed in the case of YBCOBSO near the BSO columns. In transport critical current density Jsub c angular dependence measurements, the absence of nanocolumns in YBCOY211 films resulted in the absence of a peak at 0 degrees, Jsub c Hc, in Jsub c vs theta plots, as compared to a clear peak at 0 degrees observed in YBCOBSO films with the nanocolumns. The in-field Jsub c measurements indicated small low-field Jsub c enhancements at 77K in YBCOY211 films but more than an order of magnitude improvement in high-field Jsub c in YBCOBSO films due to the differences in the microstructures.
APPROVED FOR PUBLIC RELEASE