An additional broad peak in the imaginary part of AC susceptibility of
Bi2Sr2Ca1Cu2Ox tapes is observed. Using the model of separated stacks
, it is found that the peak reflects the near grain boundary intergrow
ths of Bi2Sr2CuOx. Kosterlitz-Thouless transition temperatures of diff
erent stacks for Bi2Sr2Ca1Cu2Ox and Bi2Sr2CuOx are determined. The pre
sence of intergrowths is confirmed by the direct TEM measurements.