High Througput Screening

High Throughput Screening for the Development of New Permanent Magnets

© Fraunhofer IWM
Magnetic spin polarization at a grain boundary in a ferromagnetic metal on an atomic scale.

Dynamic growth in the field of electromobility and renewable energy has greatly increased the demand for permanent magnets made of rare earths (RE) and transition metals (TM). Due to the scarcity of the RE resources required for these technologies, attempts are being made to identify
new, intermetallic RE-TM phases. These should have good magnetic properties, and should be made of sustainable and cost-effective raw materials and be less dependent on individual RE elements.

The crystal structures of the most common permanent magnets such as Nd2Fe14B are variants of the “topologically densely packed” (TCP) phases. These TCP phases offer many possibilities for new magnetic phases: RE atoms are surrounded with TM atoms to the extent that large, direction- and temperature-stable magnetic moments are created. Such agnets can fill the gap between cost-effective ferrites and Nd2Fe14B high-performance magnets, while having the lowest RE content possible.

Simulative and experimental high throughput screening methods are applied in order to systematically examine the numerous possible RE-TM combinations for good, magnetically hard properties. The intrinsic magnetic properties, local magnetic moments and effective exchange integrals are computed or predicted at Fraunhofer IWM with a quick density functional theory (DFT) method for real and hypothetical magnet phases. Literature and data bases provide many crystal structures for TCP phases as input data for DFT simulators. A first new RE-TM phase could be theoretically predicted and experimentally confirmed. This is an indication of a high success potential of physical material modeling with regard to new high-performance magnets.