Hg系超伝導体のグレインと交流帯磁率特性(電気情報工学科)

Abstract

High-T_c ceramics are composed by two regions, grains and intergrains and the characteristics are determined by the combination of their properties. The main cause of the degradation of superconducting characteristics originates in the weak superconducting intergrain among the grains. A quantitative analysis of the contribution due to the grain and link should be made and the grained Bean model is proposed, where the superconducting phases are immersed in the matrix link superconductor. This model gives a variety of complex AC susceptibility curves. Double peaks appearing in the imaginary part χ" of the AC susceptibility and the shoulder transition in the real part χ' are well traced by this model. Comparison of observed curves in Hg-1223 superconductors allows more clear insight on the grain and intergrain characteristics.