| 摘要 |
PROBLEM TO BE SOLVED: To obtain an oxide superconductor having a high irreversible magnetic field and high critical current density at a high temp. in a high magnetic field by using an oxide contg. Bi, Pb, Sr, Ca and Cu as constituent metallic elements and specifying the ratio of Pb:Bi. SOLUTION: This oxide superconductor is made of an oxide contg. Bi, Pb, Sr, Ca and Cu as constituent metallic elements represented by the formula, Bix Pby Srp Caq Cu2 Oδ(where 1.8<=x+y<=2.5, y:x is 0.2:1 to 0.7:1, 2.5<=p+q<=3.5 and 7<=δ<=9) and has a laminar internal structure obtd. by alternately laminating platy crystal regions N each having 50-1,000Åthickness and a relatively high concn. of Pb and platy crystal regions M each having 100-2,000Åthickness and a relatively low concn. of Pb in the direction of the b-axis of each crystal or in a direction inclined from the b-axis toward the a-axis.
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