Role of spinodal-like wrinkling as a prenucleation process in crystallization of sol-gel derived thin films

摘要

Studies of crystallization of a sol-gel derived alumina thin film showed on a critical role of spinodal-like wrinkling. The wrinkling that depends on a humidity gradient in the film provides nucleation sites with high supersaturation located at the top of topological islands that occur as a result of the wrinkling. Nucleation of crystal nuclei takes place at these sites at a significantly lower temperature as it would be the case for homogenous nucleation. The crystal growth continues through different supersaturation regimes that are defined by the wrinkling topology. We showed how the crystallization can be efficiently suppressed to higher temperatures by minimizing the humidity gradient in the dip-coated film by controlled drying.