Microstructure dependent microwave properties of spray deposited Tl–Ba–Ca–Cu–O films

Tl-based superconductors are found to be the potential candidate for enormous applications especially in field of microwave devices. Thick Tl-based single phase (2 2 2 3) superconducting films have been prepared successfully on CeO 2 buffered Al 2O 3 substrates by two-step technique consisting of spray pyrolysis followed by thalliation. The modifications in structure and morphology by changing reaction conditions were studied. The microstructures were found to be sensitive to synthesis conditions and in turn their dependence on surface resistance of films. The microwave absorption properties were studied in the frequency range from 1 GHz to 10 GHz. The surface resistance of Tl–Ba–Ca–Cu–O films at room temperature was measured with the help of stripe line technique and found to be 14.9 mΩ/cm 2. The effects of microstructure on microwave absorption peaks are studied and results are discussed at the length in this paper.