Josephson bicrystal junctions on sapphire substrates for subMM waves receiver

This paper presents the results of fabrication and characterization of cuprate Josephson junctions on sapphire bicrystal substrates both at dc and sub mm waves. The Josephson junctions were fabricated on the r-cut sapphire bicrystal substrates consisting of two crystals for which the direction for both parts were misoriented at the angles/spl plusmn/12/spl deg/ to the plane of interface. The YBCO was grown at T=750-770/spl deg/C by dc sputtering at high oxygen pressure (4 mbar) after the CeO/sub 2/ epitaxial buffer layer magnetron sputtering at T=600-750/spl deg/C and pressure 0.01mbar in an Ar/O/sub 2/ mixture. The amplitude-frequency characteristics (AFC) for the junction coupled with log-periodic antenna was obtained from the ratio of the detector and the Halley sell measured signals.