The Influence of Structural Inhomogeneities on Intragranular Properties   of Y- and Bi-based Superconductors
  The measurements of temperature dependence of AC magnetic susceptibility were used to study the influence of inhomogeneities on intragranular superconducting properties of YBa2Cu3-xMxOy (M=Fe,x=0.005; Al,x=0.01; Cr,x=0.01), Bi1.7Pb0.2Sb0.1Sr2Ca2Cu3Oy and Bi1.5Pb0.3Sb0.2Sr2Ca2Cu3Oy ceramics. It is found that step-like regions are revealed on AC magnetic field dependence curves Tmg(ho) of hysteresis losses peak temperature for superconducting granuls. The steps at temperature scale depend on sample's composition as well as on the type of atoms sabstituted for the copper. They range from 1 to 2 K for Y-based and about 5 k for Bi-basedsamples. Possible interpretation of the obtained results is presented. 
V. A. Grigoryan