Experimental studies and modeling of Pb–Zr–Ti–O film growth in pulsed laser deposition

Abstract

The growth rate and composition of films deposited by laser ablation of Pb(Zr0.65Ti0.35)O3, both in vacuum and in ambient oxygen and argon with laser fluences in the range 0.3–3.0 J/cm2, were studied experimentally with using energy dispersive x-ray analysis. The film growth rate increased in vacuum with an increase in laser fluence and demonstrated two modes of behavior upon adding gas: decreased at low laser fluence and increased nonmonotonously at high laser fluence. Deposition in vacuum resulted in Pb-deficient films with the Pb/Ti ratio decreasing with an increase in laser fluence, while deposition in a gas resulted in a strong increase of Pb content with the Pb/Ti ratio increasing faster under strong laser irradiation. Changes in the film growth rate and composition were similar upon adding either oxygen or argon. No noticeable changes in the spatial distribution of the film growth rate and composition were found in a gas ambient with respect to a vacuum ambient. The obtained experimental results were analyzed using a phenomenological description of the film growth as a sorption of ablated species on the substrate surface and assuming the species retarding in a gas, with respect to vacuum, due to collisions of the species with gas molecules.