Reliable high-T_c ramp-edge junctions with a Ga-doped YBCO barrier were successfully fabricated. The junctions were composed of YBCO/Ga-YBCO/STO/YBCO on LaAlO_3 single crystals. It was shown that the resistivity of YBCO could be increased by substituting Cu by Ga into the chain layers. The RSJ behavior was observed in 200-A-thick 7 % Ga-doped YBCO barrier junctions. The junction resistances are proportional to the barrier thickness and the interface resistances increase with increasing barrier thickness. The temperature dependences of critical currents) and junction resistances(R_n) are consistent with the behavior predicted by the conventional proximity effect. The critical currents of the Ga-doped junctions were less sensitive to the variation of the barrier thickness compared to those of the other junctions. The increase of the barrier resistivity by Ga-doping resulted in an enhancement of the I_cR_n values, up to 420 μV at 50 K for 200-A-thick YBa_2Cu_(2.79)Ga_(0.21)O_(7-δ).
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机译：成功制造具有GA-掺杂YBCO屏障的可靠的高T_C斜面连接。该交界区由Laalo_3单晶的YBCO / GA-YBCO / STO / YBCO组成。结果表明，通过将Cu通过Ga替换为链层，可以增加YBCO的电阻率。在200-A厚的7％GA掺杂的YBCO屏障结合中观察到RSJ行为。结电阻与阻挡厚度成比例，并且界面电阻随着阻挡厚度的增加而增加。关键电流的温度依赖性）和结电阻（R_N）与传统接近效果预测的行为一致。与其他连接相比，Ga掺杂的结的临界电流对阻挡厚度的变化敏感。通过Ga-掺杂的阻挡电阻率的增加导致I_CR_N值的增强，在50k，对于200倍的YBA_2CU_（2.79）Ga_（0.21）O_（7-Δ），高达420μV。
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