SYNTHESIS BY CHEMICAL ROUTE AND CHARACTERIZATION OF SINGLE-PHASE PUREAND ZINC-DOPED BI2-Y-ZCA1+Z(CU1-XZNX)(2)O-8+DELTA(YSR2)

Pure and zinc-doped Bi2+ySr2-y-zCa1+z(Cu1-xZnx)(2)O-8+delta with nomin al zinc content 0 less than or equal to x less than or equal to 0.1 ha ve been synthesized by an original process based on spray-drying of a nitrate solution of the cations partially complexed with EDTA at pH gr eater than or equal to 6. The formation of the ''2212'' phase is nearl y complete at 800 degrees C. One thermal treatment at 845 degrees C gi ves materials with less than 0.5 vol. % of secondary phases for the 2. 05: 1.9: 1.05:2 composition, as shown by X-ray diffraction, SEM and ED X. In the zinc doped samples, saturation occurs for x less than or equ al to 0.025 whichis less than for YBa2(Cu1-xZnx)(3)O-7-delta (x = 0.12 ). In contrast to YBa2(Cu1-xZnx)(3)O-7-delta, Tc is stabilized for x > 0.01.