Enhanced performance tunability of films via pulsed laser deposition with a variable target-to-substrate distance at high laser fluences
Phys. Rev. Materials 10, 104802 – Published 26 October, 2026
DOI: https://doi.org/10.1103/zxb2-z39d
Abstract
The established guiding principle for pulsed laser deposition (PLD) of high-quality (YBCO) superconducting films suggests that the optimal target-to-substrate distance (TSD) lies near the visible tip of the laser-induced plume, with deviations from this point expected to degrade film properties. We modified our PLD system to allow precise external TSD adjustment over a 110-mm range and systematically studied its influence on the microstructure and electromagnetic properties of YBCO thin films. Our analysis, referencing plume-propagation models and growth processes, reveals that the optimal TSD range can, in fact, be extended under a relatively high laser fluence, depending on the desired film performance and properties. We identify four TSD regimes, each exhibiting unique film characteristics. Notably, we demonstrate that high-quality superconducting properties and crystallinity are preserved across a broad 50-mm TSD window, yielding films with variable thickness and surface structures. This tunability enhances the potential for applications in electronics and high power handling, where tailored combinations of surface structure and/or electromagnetic properties are required. Furthermore, we propose that TSD-dependent variations in flux and growth rate provide a straightforward and effective approach to probe plume (plasma) composition during laser ablation, offering insights into deposition dynamics.
