Effect of the different precursor powder on the superconducting property of Bi-2223/Ag tapes

Two kinds of precursor powder were studied: one was a mixture of Bi-2212 and CaCuO₂ and the other was a mixture of Bi-2201 and CaCuO₂. By comparing the formation rate of Bi-2223 synthesized by two kinds of precursor powder, results indicated that the mixture of Bi-2212 and CaCuO₂ was best phase assemblage of precursor powder; it could form the Bi-2223 phase rapidly. Concerning the mixture of Bi-2212 and CaCuO₂, the content of CaCuO₂ would affect the superconducting property of Bi-2223/Ag tapes, the I_c value (77 K, self-field) would increase with increasing the content of CaCuO₂ when the additional content of CaCuO₂ was smaller than 10%. If the additional content of CaCuO₂ was larger than 10%, the I_c of Bi-2223/Ag tapes (77 K, self-field) would decrease. But it was very interesting that the I_c-B curve would move to high magnetic field with increasing the content of CaCuO₂, even if the additional content of CaCuO₂ was larger than 10%. It showed that adding the additional CaCuO₂ could enhance the flux pinning of Bi-2223/Ag tapes.