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The influence of the addition of B 2 O 3 on the properties of the oxide ceramic materials Bi–Pb–Sr–Ca–Cu–O was investigated. The samples with nominal com-posi-tion Bi a Pb b B c Sr 2 Ca 2 Cu 3 O x ( a = 0.8–1.6, b = 0.06–0.26, c = 0.05–1.0) were prepared and studied by the measurement of the temperature dependence of the electrical resistivity and critical current density. The addition of a small amount of B 2 O 3 ( c = 0.05, a = 1.8, b = 0.26) had positive influence on the critical current density. On the other hand, a high content of boron ( c > 0.6, b = 0.26, a + b = 1.8) reversed the superconductor to an insulator. |
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