In this study, the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy superconductors with x = 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 were synthesized at annealing times of 32, 48, 64 h using a sol-gel method. Then, the effect of Ba doped, the annealing times, ac magnetic fields and frequencies in
the improvement of the coupling between grains of the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy (BPSBCC) superconductors were studied. In order to determine annealing temperature, TGA analysis of x = 0.0 was performed. The structural and ac magnetic susceptibility prepared samples were characterized using an X-ray diffraction, an ac susceptometer and scanning electron microscopy (SEM). The results of ac magnetic susceptibility and structural of the samples indicated that the improvement of the coupling between grains and the stability of the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy superconductors with value of x = 0.2 at 845 °C for 48 h have been increased.