Department of Physics & Astronomy, McMaster University, Hamilton, Ont., L8S 4M1, Canada
Abstract:
Magnetic susceptibility, X-ray diffraction and resistivity measurements of the system Bi1.4Pb0.6Sr2Ca2?xGaxCu3Oy are reported for 0 x 2. The high-Tc 2223 phase with a Tc of 107 K for x = 0 exists for x 0.3. The low-Tc 2212 phase with a Tc of 75 K for x = 0 exists for the full range of x. The highest values of the critical temperature and the largest volume fraction of the low-Tc phase in compounds with Ga occur for x = 0.5 ± 0.1. The identification of CaO by X-ray diffraction for x 0.6 indicates that Ga replaces Ca in the compound.