Superconducting properties were discussed in connection with microstructure for the grain oriented Bi-based high- and low-
Tc tapes prepared by both Ag sheath method and doctor blade method. For the high-
Tc tapes, grain oriented microstructure was obtained by applying the combination of cold rolling and sintering. For the low-
Tc tapes, on the other hand, grain orientation was attained by the partial melting method. Critical current density
Jc was significantly improved by the grain orientation for both high- and low-
Tc tapes. Especially, the low-
Tc tapes show excellent coupling properties of grains, leading to the large
Jc above 10
4A/cm
2 at 77K and zero magnetic field. However, at 77K, magnetic field dependence of
Jc was very large both for high- and low-
Tc tapes. At 4.2K, on the other hand,
Jc was much less sensitive to magnetic field. Maximum
Jc at 4.2K was 9×10
4A/cm
2 at 10T and 6.8×10
4A/cm
2 at 23T for low-
Tc tapes prepared by the doctor blade method. The results indicate that grain oriented Bi-based oxide superconductor is very promising for the high field superconducting magnet.
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