In situ study of diffusion-controlled phase formation and grain growth in functional Heusler/perovskite materials using multimodal synchrotron-based techniques

• Applicants: Ana Guilherme Buzanich, Ph.D.; Dr. Sabine Wurmehl
• Subject Area: Synthesis and Properties of Functional Materials ; Solid State and Surface Chemistry, Material Synthesis
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 516426808

The synthesis of a material with specific properties often requires a diffusion-controlled process in the solid state at elevated temperatures. The diffusion process enables the formation of a certain phase with a defined composition or a material with a certain structural order or promotes grain growth. The products of such a diffusion process are usually characterized ex situ under ambient conditions. If the synthesis route is still unknown, the investigation of the synthesis parameters becomes an iterative trial-and-error loop. This is where our project comes in, as it relies on the direct in-situ monitoring of the diffusion processes during the synthesis and growth of inorganic functional materials. As the iterative trial-and-error experiments for the synthesis of multicomponent systems are avoided, our study will efficiently save valuable resources and possibly even accelerate the discovery of new materials. To this end, this project pursues two directions: (1) In-situ monitoring of phase formation and grain growth of complex multicomponent materials at elevated temperatures using synchrotron-based techniques; (2) the implementation of a multimodal analytical approach with optimized "machine learning" -based data interpretation. We will focus on functional inorganic materials with strong property relationships, namely intermetallic Heusler alloys and oxide double perovskites, both with high spin polarization. We use these as model systems to study disorder phenomena and the growth of their nanoparticles (NPs) in carbon nanotubes (CNTs). The combination of the expertise between chemistry, physics and materials science provided by the applicants Dr. Ana Guilherme Buzanich (BAM) and Dr. Sabine Wurmehl (IFW) will help make the project a success through diverse scientific perspectives and skills. The project offers two very attractive PhD projects as it combines chemistry at the forefront of synthesis development and high-quality multimodal analysis techniques that will give the two PhD students a broad knowledge of interdisciplinary methodologies. Our results will be available to researchers across physical materials science that can be immediately applied to catalysis, energy-related materials, and other functional materials.

• DFG Programme: Research Grants