화학공학소재연구정보센터
Journal of Materials Science, Vol.33, No.9, 2365-2369, 1998
Fabrication and transport properties of long-length doped Bi1.7Pb0.3Sr2Ca2-xMxCu3Oy conductors (M=B, Nb or Ag)
Long lengths of Bi-2223 conductors doped with Ag, Nb and B were fabricated. The recrystallization of the glasses during various heat treatments was studied by differential thermal analysis (DTA), differential scanning calorimetry, X-ray diffraction and resistivity measurements. Activation energies and frequency factors for crystallization were determined by non-isothermal DTA, employing different models. It was found that both the peritectic transition and the reaction rate were dependent on the ambient atmosphere. Kinetic studies under different atmospheres revealed that the thermal stability of Bi-2223 was greatly enhanced under an oxygen atmosphere. J(c) measurements at 77 K showed an increase on silver addition. Furthermore it was found that the silver addition does not destroy the superconductivity.