Fabrication and characterisation of novel substrates and superconducting thick films

Novel substrates RESrA104 for BSCCO thick films have been synthesized using the solid state reaction method. Single phase samples of this compound can be easily formed at temperatures between 1350-1500 °C in air. Highly dense samples can be achieved by increasing the sintering temperature. The dielectric constant 8 and dielectric loss of NdSrA104 have been measured at room temperature with £ =15.7, and tan 5 = 6x10-3 over a wide frequency range from 30 Hz to 13 MHz. Results show that NdSrA104 has a good microwave performance within the measured frequency range. Chemical compatibilities between RESrA104 and Bi2212 have been investigated by mixing powders of RESrA104 and Bi2212 and sintering at high temperatures up to 890°C in air for more than 6h. XRD results show that all peaks are from either RESrA104 or Bi2212, and no extra peaks can be found. This indicates that RESrA104 is very compatible with Bi2212.