CAREER: Leading to Accelerated Discoveries in High-Throughput Ultrafast Laser-Driven Processing of High Entropy Alloy Nanoparticles

Oklahoma State University, Stillwater OK

Investigators

Abstract

This Faculty Early Career Development (CAREER) award supports fundamental research that enables high-throughput creation of high entropy alloy nanoparticles (HEA NPs). HEA NPs are structures where multiple elements (typically five or more) are homogeneously mixed at nanoscale dimensions. This technique of fabricating NPs offers access to a large number of compositions of HEAs that have the ability to form unique microstructures, leading to new physical properties which can be applied in areas like catalysis in order to reduce the energy consumption of industrial processes. A key challenge to realizing the unique potential of HEA NPs is the lack of manufacturing processes that can access a large compositional and dimensional space of NPs and advance the fundamental understanding of process-structure-property correlations. This research project will aim to develop a laser-driven method that reliably allows the generation of HEA NPs with control over broad composition and size ranges. This project aims to generate extensive material libraries of HEA NPs, which can accelerate research to understand the across-the-scale (atomic-to-nano) structure of NPs and their correlation with the electro- and plasmonic catalytic properties. The integrated educational program of this project will disseminate the research activities to a broad community of students and teachers at the K-12, undergraduate, and graduate levels. These initiatives aim toward increasing the skilled workforce of engineers with improved participation of underrepresented American populations. This project aims to develop a high-throughput methodology to create HEA NPs with large compositional and dimensional space by employing a nanosecond pulsed laser-driven particle formation method. The pulsed laser processing on combinatorial multilayer/alloy ultrathin films (1-30 nm) facilitates the fabrication of well-defined isolated droplet-shaped HEA NPs of various compositions on substrates. These NPs are formed through the laser-induced melt-phase dewetting phenomenon, coupled with thermally-driven mass transport and ultrafast solidification in the nanosecond timescale. The success of this hypothesis-driven methodology will facilitate an accelerated fundamental understanding of the formation mechanism, governing factors, elemental distribution, and microstructures. The utilization of conventional and advanced data science driven characterization methods, such as 4D scanning transmission electron microscopy, will resolve the compositional and microstructural complexities to fill the knowledge gaps in understanding laser-material interactions for creating NPs. These results will have broader implications for advancing the fundamental science of microstructure correlations with the electro- and plasmonic catalytic properties of HEA NPs. The project will lead to the creation of new material libraries for HEA NPs and open up future opportunities for applications in catalysis and other areas. This project is jointly funded by the Advanced Manufacturing Program, the Established Program to Stimulate Competitive Research (EPSCoR), and the Metals and Metallic Nanostructures Program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.