Controlled partial melting of dipcoated Bi-2212/Ag ribbons for combined isobaric and isothermal processing in reduced oxygen atmospheres

摘要

A detailed study has been made of the control and optimisation of partial melting of dipcoated Bi-2212/Ag ribbons using reduced oxygen partial pressures. A coulometric titration technique has been employed to vary the oxygen partial pressure in a region of the phase diagram corresponding to binary melting and the amount of partial melting has been quantified. It has been shown that complete melting of the Bi-2212 for short time periods is required for achieving optimum ribbon microstructure. The information has been used to process ribbons using either or both isothermal and isobaric methods. The combined method was found to be most effective Fully connected ribbons with only minor quantities of second phases have been obtained.