Study of the melt-textured growth process in Bi system superconductors

A new melting technique, so called a "floating heat zone melting - directional solidification" method, has been developed for texture formation in samples of Bi system superconductors. The effect of various factors on texture formation have been studied in detail. The results show that the precursor powder's molar ratio of metal ions, melting temperature, and floating speed significantly affect the texture of the Bi - 2212 samples. Bi - 2212 crystals of good quality have been obtained at a melting temperature of 880°C and sample moving speed of 8 mm/h. But, the method is not suitable for the growth of textured Bi - 2223 crystal.