Properties and microstructures of melt-processed (YHo)Ba2Cu3O7-y superconductor

The authors have prepared (YHo)Ba2Cu3O7-y superconductors with high Jc by the powder melting process (PMP) method. The DTA result shows that the melting temperature of Y-system superconductor can be reduced by Ho addition. The Jc value can be improved and the size of the 211 phase can be reduced by Ho substitution. Microstructures and the X-ray diffraction pattern indicate that the 123 grains are preferentially aligned with mutually parallel a-b conductive planes. There are many twins and fine 211 particles in the sample. Many crystal defects are also found to exist around the 211 phase. These defects may be acting as pinning centres.