Author/Authors :
T.، Saitoh, نويسنده , , T.، Araki, نويسنده , , T.، Muroga, نويسنده , , T.، Niwa, نويسنده , , Y.، Iijima, نويسنده , , Y.، Yamada, نويسنده , , Y.، Shiohara, نويسنده , , I.، Hirabayashi, نويسنده ,
Abstract :
We investigated calcining conditions for YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) films by metalorganic deposition using trifluoroacetates. We measured residual carbon content by secondary ion mass spectroscopy (SIMS) and critical current density J/sub c/ values of the films calcined with various heat treatments. Precursor films are decomposed in calcining duration at 200 to 250(degree)C, and simultaneously harmful residue such as carbon content is generated. SIMS results of carbon intensity show calcination is more effective than extension of the duration at 200 to 250(degree)C to reduce carbon content. J/sub c/ values of films with the calcination varied with the duration, reaching a maximum at about 10 hours. The J/sub c/ values of the films depend on decomposition of trifluoroacetates and CuO nanocrystallites growth, rather than the influence of carbon content. We have succeeded in fabricating the YBCO films of 217 to 241 nm thickness with high J/sub c/ values; 1.7 to 2.9 MA/cm/sup 2/ (77 K, 0 T) on CeO/sub 2//Gd/sub 2/Zr/sub 2/O/sub 7//hastelloy -C.
Keywords :
Abdominal obesity , Food patterns , Prospective study , waist circumference