Heating rate effect on the evolution of texture in (Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀ Ag-sheathed tapes

Bi2223/Ag tapes have been produced by the powder-in-tube technique. The evolution of texture during the first heat treatment has been studied by means of in situ synchrotron radiation diffraction. Using various heating rates (1, 2 and 4 degrees C min(-1)), it wag found that the kinetics of preferential orientation development during the early sintering period was slower when low heating rates were used. Microstructural observations indicate that this effect is related to the enhanced growth of Bi2212 grains during the final stage of the heating ramp. Increasing the heating rate results in a faster disappearance of the Bi2212 phase, which in turn is supposed to induce a faster rate of liquid phase formation at the beginning of the reaction process leading to the development of the Bi2223 phase. This feature is also believed to play a role in the texturing kinetics.