Phase formation and microstructure of silver-sheathed B(Pb)SCCO tapes influenced by Te additive

The influence of tellurium (Te) addition to the Bi-Pb-Sr-Ca-Cu-O (B(Pb)SCCO ) system on its microstructure and phase formation is investigated. Electro n probe microanalysis and scanning electron microscopy analyses show Te dif fusion from the superconducting core into the silver sheath of the B(Pb)SCC O tapes. It is established that the initial Te presence in the core does no t lead to any essential changes with respect to the superconducting transit ion temperature (T-c) and critical current density (J(c)). However, Te addi tion appears to be a supporting factor for 2223 phase formation and crystal growth. Final Te incorporation in the silver sheath has an additional stre ngthening effect on the sheath that makes it more stable to external mechan ical damages and gives the opportunity for better protection of the superco nducting core.