الملخص

Abstract Samples of the high temperature superconducting system, Bi2Ba2Ca2Cu3O10, were prepared by solid state reaction method with different sintering temperatures (810, 830, 850, 870, 890) Co. X-ray diffraction technique was used to examine the structure of the compound and showed that the sample prepared with sintering temperature at 850 Co exhibits tetragonal phase with the lattice parameters a = b = 5.42 Ao, c = 34.13 Ao. The electrical resistivity measurements exhibited that the sample prepared at 850 Co its critical temperature was Tc=120K and decreases to 87K when prepared at 870Co. However when the same sample prepared at 890 Co it showed semiconducting behavior with two activation energies (8.593 - 3.456)meV. The effect of annealing on critical temperature has been investigated on the sample which was prepared at 850 Co. The best value of Tc was (132)K at the annealing temperature 400 Co, and rises to 140K with increasing the annealing time from 24 hrs to 72hrs and this increase might be caused by the increase of oxygen content or by intergrowths of a large number Cu-O layers in the cell.