Observation of high-temperature superconducting phases in Bi-Pb-Sr-Ca-Cu-O system synthesized using solar energy and superfast melt quenching

Temperature dependence of dissipation and oscillation period of a superconductive cylindrical HTSC sample of Bi-Pb-Sr-Ca-Cu-O system suspended by a thin elastic thread and performing axial-torsional vibrations in a transverse magnetic field were studied. Above the critical temperature of a main phase Bi(2223) of superconductive transition with T_c=107K a ''chaos'' region was observed in temperature interval 107-150K where some separate bursts of frequency and dissipation of oscillations were fixed. It is supposed that the ''chaos'' region may point to the possibility of the existence of other magnetic or more high-temperature phases in small concentrations as single separate islands in the normal material of 2223 - phase. (author)