Volt-ampere characteristic of high temperature superconducting ceramics

Methods of current-voltage characteristics and magnetization in quasistationary magnetic field were used to study current-carrying ability and character of transport current in porous HTS-ceramics YBa2Cu3Ox. It is shown that the form of current-voltage characteristic can be determined by ceramics heterogeneity, namely by the process of filling of superconducting current clusters of ultimate sizes by transport current. These current clusters are connected with other clusters by noticeable resistive barriers and form the net of current wayes (clusters) of superconducting ceramics