The Bi_2Sr_2Ca_n-1Cu_nO_x (BSCCO) family is one of the most investigated high-temperature superconductors with a perovskite structure. At this time, three stable superconducting BSCCO phases are known: Bi_2Sr_2CuO_x (2202), Bi_2Sr_2 CaCu_2O_x (2212), and Bi_2Sr_2Ca_2Cu_3O_x (2223). The critical temperature of the superconductive transition T_c rises when the number of Ca-Cu-O planes n is increased. Its value is 10K, 95K, and 110K for 2201, 2212, and 2223 phases, respectively. The members of the BSCCO family with n>3 have not been studied systematically. However, decrease T_c with increasing n or missing superconductivity has been established in artificially deposited structures with n>3. This fact is explained often by the decrease of the density of holes and by an increasing number of crystal defects [1-4]. There are, however, a number of papers where the singularities in temperature dependence of the density of holes and by an increasing number of crystal defects [1-4]. There are, however, a number of papers where the singularities in temperature dependence of the resistance have been attributed to the presence of microinserts of the superior phases with n>3 [5-6]. The singularities in the temperature dependence of the resistance of the samples were obtained preparing the 2212 superconductive ceramic from a nonstoichiometric mixture of the precursors containing excess calcium and copper, briefly reported in [7-9]. In this paper the details concerning preparation, crystal lattice parameters, stability of the superconductive 2212-phase ceramics containing microinserts of the superior phases with n>3 and their electrical characteristics are given. Some theoretical speculations concerning possible superconductivity in superior phase filaments are presented.
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