Dependence of the critical temperature of laser-ablated YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> thin films on LaAlO<sub>3</sub> substrate growth technique
J D Warner; K B Bhasin; F A Miranda; J D Warner; Lewis Res. Center, NASA, Cleveland, OH, USA; K B Bhasin; Lewis Res. Center, NASA, Cleveland, OH, USA; F A Miranda; Lewis Res. Center, NASA, Cleveland, OH, USA
Журнал:
Superconductor Science and Technology
Дата:
1990-09-01
Аннотация:
Samples of LaAlO<sub>3</sub> made by flame fusion and the Czochralski method were subjected to the same temperature conditions that they have to undergo during the laser ablation deposition of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7- delta </sub> thin films. After oxygen annealing at 750 degrees C, the LaAlO<sub>3</sub> substrate made by the two methods experienced surface roughening. The degree of roughening on the substrate made by the Czochraiski method was three times greater than that on the substrate made by flame fusion. This excessive surface roughening may be the origin of the experimentally observed lowering of the critical temperature of a film deposited by laser ablation on a LaAlO<sub>3</sub> substrate made by the Czochralski method with respect to its counterpart deposited on a LaAlO<sub>3</sub> substrate made by flame fusion.
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