POLYTYPOIDIC STRUCTURE OF THE Bi-SYSTEM HIGH-T_c SUPERCONDUCTORS AND THEIR SUPERCONDUCTIVITY
Bi系高T_c超导材料的类多型结构及其超导电性

Some studies of the polytypoidic structure in Bi-system superconductors byX-ray precession photographs,electron diffraction and TEM technique are made.A strongincommensurate modulation reflections were observed by these methods in Bi-system 2223phase.The