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The theoretical Chemical Physics program at Ames Laboratory supports integrated efforts in electronic structure theory and non-equilibrium statistical mechanical & multiscale modeling. The primary focus is on the development and application of methods that enable the study of surface phenomena, heterogeneous catalysis, cluster science and nucleation theory, and mechanisms in organometallic chemistry.
Vladimir Antropov, Kai-Ming Ho, Matthew J. Kramer, R. William McCallum, Cai-Zhuang Wang
In order to enable domestic automobile makers to offer a broad range of vehicles with electric drive motors with either hybrid or purely electric motor drives, this project will utilize a demonstrated science‐based process to design and synthesize a high energy product permanent magnet of the alnico type in bulk final shapes without rare earth elements that will be competitive with existing commercial RE‐based magnets on a cost per MGOe per Kg basis and will have a more sustainable long term supply and cost outlook.The keys to improving coercivity in the alnico family, its main deficiency, will be further unraveled using experimental alnico samples (either chill cast, melt spun ribbon, or pre‐alloyed powder processed) and detailed characterization tools, and state‐of‐the‐art computational modeling and simulation (including Genetic Algorithm atomistic phase stability calculations, kinetic Monte Carlo interface calculations, phase field transformation modeling, and meso‐scale magnetics modeling).
Improved alnico will require alloy design changes, specifically targeted to minimize the content of Co, which is the most expensive component, to select alloy additions that boost coercivity, and to explore the use of an “X” addition to the Fe‐Co phase that induces magneto‐crystalline anisotropy. Also, magnet processing changes will be developed that move away from the need for machining of final magnet shapes and move toward the ability for mass production. The outcome of the new research probably will replace the conventional methods of bulk alnico magnet fabrication: 1) casting in a special mold with directional cooling capability, or 2) powder metallurgy processing by an elemental blend approach with new powder processing approaches that starts with pre‐alloyed alnico powder and result in net‐shape bulk magnets that require little if any post‐processing machining or grinding.
This research is supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy.
This project will help incorporate our new, efficient, order-N (where N is the number of scattering sites in a defected crystal) method for solving the Poisson’s equation for site-centered electronic-structure method used within the center (i.e., the LSMS code) for critical simulations. The method will be extended in collaboration to develop capabilities for relaxation by atomic forces within this new formulation for full quantum simulation of large-scale defected systems.
This research is supported by the U.S. Department of Energy, Office of Basic Energy Sciences. The Energy Frontier Research Center is funded through the US DOE Oak Ridge National Laboratory.
The project proposes a new solid state processing technology which will transform how current magnets are fabricated, resulting in a dramatic cost decrease and significant reduction of the rare earth (RE) content while actually enhancing the magnetic performance of the magnets. This will be accomplished by a revolutionary solid-state processing technique called Friction Consolidation and Extrusion (FC&E). Processing of sintered (Nd, Dy)-Fe-B type magnets in use today require 2-4 wt.% excess RE elements relative to the stoichiometric compound, with up to 4-10 wt. % of the alloy being Dy. The new class of exchange coupled hard / soft nanocomposite magnets have been theoretically predicted to be twice as strong as the current state of the art rare earth magnets, while the total RE content can be reduced by 30% or more. The challenge remains to develop a reliable and economical process to produce a 100% dense alloy with nanoscale grains, full magnetic alignment and a uniformly distributed nanoscale soft magnetic phase. The role of The Ames Laboratory will be to 1) determine optimal length scales of the nano-structuring using advance computational tools, 2) provide feedstock for the FC&E process, 3) characterize high performance magnet alloys produced by the PNNL for their microstructure and phase distributions using scanning electron microscopy (SEM), electron probe micro-analysis (EPMA) and Transmission electron microscopy (TEM).
This research is supported by the U.S. Department of Energy, Advanced Research Projects Agency-Energy.
The proposed research addresses the Warm Dense Matter area identified in the Report of the ReNeW in HEDLP. The electronic structure, equation of state, radiative, and transport properties of warm electrons in an amorphous or disordered configuration of ions are not well described by either solid state or plasma models. Such warm-dense systems share the characteristic of the solid state that multi-center scattering effects are of paramount importance in forming bands of valence states, but furthermore require the description of an appreciable occupation in higher energy and angular momentum channel continuum states.
This research is supported by the U.S. Department of Energy, Office of Fusion Energy Sciences.