Preparation of Lu-123 thin films by pulsed laser deposition for interface-modified Josephson junctions

Preparation of LuBa2Cu3Oy (Lu-123) thin films by a pulsed laser deposition (PLD) technique was studied. Thin films with c-axis orientation were successfully obtained on SrTiO3(1 0 0) substrates at a relatively low temperatures of 600-660 deg. C. These films exhibited a Tc(zero) of 82 K. We fabricated interface-modified ramp-edge Josephson junctions using the Lu-123 and La-doped Y-123 for counter and base electrodes, respectively. The Lu-123 electrode was deposited at 635 deg. C. The obtained junctions exhibited RCSJ-type current-voltage characteristics. The Lu-123 electrode without a ground plane showed moderately low sheet inductance of 3 pH/□