EFFECT OF MAGNETIC AND NONMAGNETIC IMPURITIES (NI, ZN) SUBSTITUTION FOR CU IN BI-2(SRCA)(2-XMX)(1+N)O-Y WHISKERS(N)(CU1)

We have measured the change in the resistive T-c of Bi-2(SrCa)(2+n)(Cu 1-xMx)(1+n)O-y whiskers due to substitution of M = Ni (magnetic) or M = Zn (nonmagnetic) for Cu. These whisker crystals show resistance drop s for both the 2212 and 2223 (n=1,2) phases, with transition widths (1 0-90 %) of 1 K. We checked the effect of oxygenation at several values of x, and found that T-c is maximum for the y obtained by growing and annealing in 1 atm of O-2. We observed a linear depression of T-c for both 2212 and 2223 phases with D=dT(c)/dx approximate to-800 K for bo th Ni and Zn. This is in contrast with YBCO in which D(Zn)approximate to 3D(Ni).