Tr. Thurston et al., SYNCHROTRON X-RAY-SCATTERING MEASUREMENTS OF BULK STRUCTURAL-PROPERTIES IN SUPERCONDUCTING (BI,PB)(2)SR2CA2CU3O10-AG TAPES, Journal of applied physics, 79(6), 1996, pp. 3122-3132
The structural properties of superconducting (Bi,Pb)(2)Sr2Ca2Cu3O10-Ag
(2223) tapes have been measured using synchrotron x-ray scattering te
chniques. The x-ray photon energy was tuned just below the silver K ab
sorption edge so the penetration depth was large, which allowed the me
asurements to be performed in a transmission geometry without removing
the silver cladding. Analysis of the peaks in 2 theta scans indicates
that residual (Bi,Pb)(2)Sr2CaCu2O8 (2212) superconductor starting mat
erial is present in all samples studied. The amount of 2212 varied wid
ely among the tapes, and was not homogeneous along the length of each
individual tape. Residual 2212 content increased near the ends of most
samples, suggesting that 2223 phase development is sensitive to wheth
er the superconducting material is encased in silver or not. The bulk
c-axis alignment was measured in similar to 100 mono- and multifilamen
t samples, and correlations between c-axis alignment and current carry
ing capacity at 77 K were found. Multifilament samples generally had b
etter alignment than monofilament samples. The c-axis alignment along
the length of the tapes was uniform, and the superconducting material
within similar to 1 mu m of the Ag was better textured than the bulk o
f the sample. Intermediate pressings were directly shown to have an ad
verse affect on c-axis alignment. Finally, the evolution of texture an
d phase development was examined in a series of samples annealed for v
arying times. The 2212 starting material acquired the final c-axis ali
gnment state after brief heating times, and only after much longer hea
ting times did the 2212 transform into the 2223 phase. These results a
nd their implications for improving processing procedures are discusse
d. (C) 1996 American Institute of Physics.