Highly crystalline superconducting a-axis oriented YBCO films by DC-sputtering-effects of target, template layer and substrate biasing
Highly crystalline superconducting a-axis oriented thin films of Y1Ba2Cu3O7−x (YBC) were prepared by DC-sputtering using the template layer procedure from three different targets annealed for different durations in flowing oxygen. The as-deposited films on SrTiO3(100), NdGaO3(110) and MgO(100) substrates showed a smooth surface morphology and a high critical onset temperature. A full width at half maximum value of 0.05° as measured through the rocking curve of (200) film peak on SrTiO3 substrate indicated high crystallinity for the as-prepared films. The superconducting and crystalline properties of the films were found to be dependent on the target used (mainly on the activated oxygen released from the target), quality of the template layer and substrate biasing. The template layer procedure was found to be very effective to grow a-axis superconducting films on lattice mismatched substrate MgO. Smooth film morphology also enabled the fabrication of sandwich type tunnel junctions on MgO substrates and the results of such depositions are also presented.
KeywordsBarrier Layer High Resolution Scanning Electron Microscope Smooth Surface Morphology Template Layer Rock Curve Measurement
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