Growth and surface morphology of laser ablated YBaCuO films analysed by SEM

The dependence of the surface morphology, particularly the general surface roughness, the existence of outgrowths, and the density of droplets, on preparation conditions under the requirement of retaining good superconducting properties has been investigated. The variation of the oxygen partial pressure, the substrate temperature, or the deposition rate while keeping all other parameters constant strongly influences the roughness and outgrowing of particles. The density and size of the droplets depend sensitively on the laser-target-substrate geometry, the deposition rate per pulse, the target density, and the film thickness. The study reveals that deposition parameters exist that enable good superconducting films with smooth surfaces and a droplet density below 1/(100 mu m)/sup 2/ to be obtained.<
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