Accelerating Discovery of Nanoarchitectures in Thin Films Through Laser Thermal Gradient Treatment Induced Solid-State Metal Dealloying

The Thin-film solid-state metal dealloying (SSMD) process is emerging as an innovative method for fabricating nanoarchitectured materials. Due to the solid-state processing, and unique properties of nanoscale features, which alter equilibrium thermodynamics and phase stability, SSMD enables the formation of finer feature sizes in bi-continuous nanostructures with lower temperature treatments and shorter processing times compared to liquid metal dealloying. SSMD thus opens new opportunities in applications related to thin film processes. However, the exploration of the materials library to design new dealloyed nanostructures is inefficient and often relies on experimental serendipity which limits the ability to choose appropriate engineering parameters that are connected to fundamental physical and chemical characters of the systems.<br/><br/>In this work, we present a comprehensive method to fabricate machine-learning (ML)-predicted potential systems, specifically Nb-Al/Sc and Nb-Al/Cu (an A-B parent alloy dealloyed by a C solvent metal), within a thermal gradient treatment condition ranging from 100 to 800 °C via laser heating. The high-dimensional thin-film sample was rapidly characterized through a suite of multimodal synchrotron X-ray techniques, including Grazing Incidence Wide-/Small-Angle X-ray Scattering (GIWAXS/GISAXS), and X-ray Absorption Spectroscopy (XAS). This characterization was combined with an autonomous approach utilizing ML for decision-making in the experimental search process. Subsequent Transmission Electron Microscopy (TEM) and Scanning Transmission Electron Microscopy (STEM) were carried out for detailed analysis and validation.<br/><br/>The results demonstrated critical transitions in phase and morphology across a broad thermal space, revealing a potential dealloying process responsible for the formation of the nanostructure. These findings provide valuable insights into the design of new dealloyed nanostructures, elucidating key processing conditions and enhancing our understanding of the dealloying mechanism. This includes insights into phase transitions, chemical bonding statuses, and morphological changes, thereby paving the way for more efficient and targeted development of advanced nanoarchitectured materials for future applications.