TY - JOUR
T1 - Effect of annealing DC-sputtered Bi,Pb-2223 thin films
AU - Matsumoto, A.
AU - Kitaguchi, H.
AU - Doi, T.
AU - Izumi, T.
AU - Hakuraku, Y.
AU - Shimada, Y.
AU - Hata, S.
N1 - Publisher Copyright:
© 2015 IEEE.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Thin films of Bi-2223 fabricated on SrTiO3(100) substrates by dc sputtering were found to have a transition temperature (Tc) as low as that of bulk-phase Bi-2223. Subsequent annealing of these precursor films in the presence of Bi,Pb-2223 pellets increased this Tc value from 72 to 105 K, making it comparable to bulk-phase Bi,Pb-2223. Strong (00l) peaks and a sharp quadrupole were observed in this annealed film, indicating a main phase of Bi,Pb-2223 with a c-axis orientation by the X-ray diffractometry (XRD) measurements. A maximum critical current density (Jc) of 3.3 × 105 A/cm2 at 77 K was also obtained with the Bi,Pb-2223 thin film, which is a value that is much higher than that of commercial Bi,Pb-2223 tapes. Jc values of thin films were strongly dependent on the annealing temperatures between 854 °C and 866 °C. In this temperature range, XRD data show that the thin films were not a single phase of Bi,Pb-2223, suggesting only a slight interruption of the supercurrent. Although, the films have a good c-axis and ab-axis alignments. Thus, although the films were not perfect, the improvement in microstructure allows for a much higher Jc value.
AB - Thin films of Bi-2223 fabricated on SrTiO3(100) substrates by dc sputtering were found to have a transition temperature (Tc) as low as that of bulk-phase Bi-2223. Subsequent annealing of these precursor films in the presence of Bi,Pb-2223 pellets increased this Tc value from 72 to 105 K, making it comparable to bulk-phase Bi,Pb-2223. Strong (00l) peaks and a sharp quadrupole were observed in this annealed film, indicating a main phase of Bi,Pb-2223 with a c-axis orientation by the X-ray diffractometry (XRD) measurements. A maximum critical current density (Jc) of 3.3 × 105 A/cm2 at 77 K was also obtained with the Bi,Pb-2223 thin film, which is a value that is much higher than that of commercial Bi,Pb-2223 tapes. Jc values of thin films were strongly dependent on the annealing temperatures between 854 °C and 866 °C. In this temperature range, XRD data show that the thin films were not a single phase of Bi,Pb-2223, suggesting only a slight interruption of the supercurrent. Although, the films have a good c-axis and ab-axis alignments. Thus, although the films were not perfect, the improvement in microstructure allows for a much higher Jc value.
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U2 - 10.1109/TASC.2014.2376193
DO - 10.1109/TASC.2014.2376193
M3 - Article
AN - SCOPUS:84924710000
SN - 1051-8223
VL - 25
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 3
M1 - 6967731
ER -