Title :
DC-SQUIDs of YBa/sub 2/Cu/sub 3/O/sub 7/ with artificial PrBa/sub 2/Cu/sub 3/O/sub x/ barriers
Author :
Schilling, M. ; Bade, T. ; Merkt, U.
Author_Institution :
Hamburg Univ., Germany
fDate :
3/1/1993 12:00:00 AM
Abstract :
For the preparation of Josephson junctions and DC-SQUIDs (superconducting quantum interference devices), epitaxial, c-axis-oriented YBa/sub 2/Cu/sub 3/O/sub 7/ films are deposited in-situ on SrTiO/sub 3/ substrates by laser deposition with a KrF excimer laser in a multilayer process. As insulator between subsequent superconductor layers, laser-deposited MgO films are used. The patterning is done with conventional photolithography and argon ion beam etching. The DC-SQUIDs are characterized by electrical transport measurements with and without magnetic fields. Flux modulation up to 72 K is observed. The critical current depends exponentially on the artificial barrier thickness and yields a coherence length across the junction of about 3 nm.<>
Keywords :
Josephson effect; SQUIDs; barium compounds; coherence length; critical currents; photolithography; praseodymium compounds; pulsed laser deposition; scanning electron microscope examination of materials; sputter etching; superconducting epitaxial layers; superconducting thin films; yttrium compounds; 4 to 77 K; Ar ion beam etching; DC SQUID; Josephson junctions; KrF excimer laser; SEM; YBa/sub 2/Cu/sub 3/O/sub 7/-PrBa/sub 2/Cu/sub 3/O/sub x/-MgO; artificial barrier thickness; c-axis oriented epitaxial film; coherence length; critical current; electrical transport measurements; flux modulation; laser ablation; multilayer process; noise measurement; photolithography; superconducting quantum interference devices; Insulation; Interference; Josephson junctions; Magnetic field measurement; Magnetic multilayers; SQUIDs; Substrates; Superconducting devices; Superconducting epitaxial layers; Superconducting films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
