DMREF:SusChEM:Collaborative Research: Design and Synthesis of Novel Magnetic Materials

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

Non-Technical Description: This collaborative research project will implement new, transformative strategies for the design of novel magnetic materials, with special focus on sustainable materials containing earth-abundant and inexpensive elements. The project will couple a strong experimental effort with recent theoretical advances in quantum modeling algorithms and software, data-mining techniques, and high-performance hardware to accomplish its objectives. Magnets play a crucial role in contemporary technologies. They are essential components in generators, computer hard drives, mobile devices, and in all electric motors. Because of their role in such devices, our economy depends largely on the creation of better magnetic materials. This research will focus on the discovery of new phases with anisotropic structures, high magnetization, high Curie temperatures, high spin polarization and high magnetic anisotropy. Materials with these properties will have important applications in ultra-small spintronics devices, new high-density data-storage schemes and high-energy-product permanent-magnet materials. The broader impact activities of the project will involve graduate education, maintaining contact with the private sector, and outreach to underrepresented groups and middle-school students. Specially crafted activities will include the Alice in Wonderland, Nanocamp and STEM after-school, and summer-intern programs. The algorithms, code and databases created in this research will be made available to other accelerated materials-discovery efforts. Technical Description: The technical design and synthesis of new magnetic materials is a formidable problem, especially so given the myriads of possible combinations of composition and structure. This research will use computationally driven phase-diagram explorations and materials-structure prediction coupled with experiment to identify materials with desirable properties for magnetic applications. A new adaptive genetic algorithm coupled to first-principle codes will be used for structure and property searches. The algorithm will possess the speed and efficiency of classical simulations, while maintaining the accuracy of quantum-based simulations. Concurrent, experimental research will involve novel synthetic techniques and a comprehensive set of characterization methods. With guidance from theory, nonequilibrium processes will be employed to generate rich (stable and metastable) material phases, including inert-gas condensation techniques, sputtering and pulsed-laser-deposition methods to synthesize nanoscale clusters and particles, and ultra-fast quenching from the melt to produce bulk materials. Comprehensive structural characterization of these material phases will be performed with x-ray and neutron diffraction, and high-resolution electron microscopy; magnetic and electronic-structure studies will be pursued with magnetization, x-ray magnetic circular dichroism and other methods. The characterization of these material phases is key for constructing and understanding experimental phase diagrams that will be used to validate and verify theoretical work, and provide strategies for the synthesis of new materials.