Phase transformation in doped Y–Ba–Cu–O superconductors obtained by different melt processing techniques

In order to produce superconductors with improved properties the better understanding of the phase transformations taking place during the heat treatments in the melt processing techniques seems to be important. For the examination of the phase transformation in the Y–Ba,K–Cu–O,F superconductors a Philips PW 3710 type X-ray diffractometer equipped with a HTK 16 Anton Paar type heating chamber was used. It was established, that in the melted, Y2O3 particles containing materials the most part of the Y123 phase crystallizes during the heating period of the subsequent heat treatment, but in the samples presintered at lower (900 °C) temperature the formation of Y123 phase occurs mainly on cooling. The partial substitution of Ba for K influences favourably on the crystallization of Y123.