Superconducting oxide materials with nominal composition Bi2-xSbxSr2Ca2Cu3Oy (x=0.05-0.3) and Bi1.6Pb0.4-xVxSr2Ca2Cu3Oy (x=0.1 0.4) were synthesized. It was found that after prolonged synthesis, formation of the 2223 phase in the Bi-Sb-Sr-Ca-Cu-O system is possible. However, the critical temperatures of the samples are around 90 K and are lower than those of the superconducting materials from the Bi-Pb-Sr-Ca-Cu-O and Bi-Pb(Sb)-Sr-Ca-Cu-O systems. It was also found that V inhibits the formation of the phase 2223, raises the resistance of the samples and has a negative effect on the Tc and the phase composition of the Bi-Pb(V)-Sr-Ca-Cu-O materials. © 1992 Chapman & Hall.