YBa2Cu3O7-x thin-film Josephson junctions on 2x12 degrees bicrystal(110) NdGaO3 substrates

Grain-boundary YBa2Cu3O7-x Josephson junctions with normal-state resistances from 0.1 to 10 Omega were fabricated on (110) NdGaO3 bicrystal substrates with a misorientation angle of 2 x 12 degrees. Electrical imaging of the junctions in the temperature range 80 K-300 K was performed by a technique based on laser scanning microscopy. The average values of the electrical transport parameters of the fabricated junctions were shown to be comparable to those of reference junctions made on (100) SrTiO3 bicrystals. Values of the Josephson linewidth as low as 1 GHz at 77 K have been obtained from the response of the junctions to low-intensity 94 GHz electromagnetic radiation. When high-intensity 94 GHz radiation was applied to the junctions, current steps appeared in the I-V curves at voltages V-n = nhf/2e up to 6.5 mV. These results demonstrate the applicability of YBa2Cu3O7-x grain-boundary junctions made on NdGaO3 bicrystal substrates for millimeter- and submillimeter-wave detection.