ゾル-ゲル法によるBa₂YCu₃O_7-y超電導体コンポジットの作製

抄録

The synthetic process for the composite polycrystalline Ba₂YCu₃O_7-y (abbreviated to BYCO) superconductor by the sol-gel method was discussed. The solution containing Ba²⁺-, Y³⁺-, Cu²⁺- and Si-alkoxide was changed to gel by very slow drying. The dried gels were converted to superconductor by heat treatment under low pressure of air and subsequent oxidizing in O₂ atmosphere. The sintered BYCO body had a nano-composite structure consisting of BYCO and Ba₂SiO₄ and other phases. This sintered body showed an enhanced magnetic property in the superconducting state because of introduction of pinning centers. On the other hand, composition control to avoid the segregation of a secondary phase at grain boundaries was effective in increasing the conductivity of superconducting transport current.