High Frequency Characteristics of 1-2-3 Films on MgO Substrates Grown by Activated Reactive Evaporation
One important application of the thin film high temperature superconductors is in the area of passive components for high frequency (microwave) devices. The important parameter that characterizes the ohmic losses in the superconductor film at these frequencies (1–100 GHz) is the surface resistance (Rs). It has been reported earlier that extremely high quality films are required to compete with copper at 100 GHz [1,2]. Films that exhibit excellent Rs values were usually grown by laser ablation at 750–780 ° C on exotic low loss substrates such as LaA1O3. In these films, c-axis orientation was well formed, defects were minimal, Tcs’ were higher than 90 K, Jcs' higher than 106 Amps/cm2 at 77 K etc.. In fact, the films were reported to be nearly single crystal with less than 1% impurities. In this letter we report our results of Rs measurement on 1-2-3 films grown on MgO substrates at 675 ° C, and show that some of the stringent conditions can be met more easily using the low pressure ARE growth process. The process is well established, and has been used successfully to fabricate high quality YBCO films [3, 4].
KeywordsSurface Resistance Ohmic Loss Superconductor Film Post Deposition High Quality Film
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