Invited
ACCELERATED DISCOVERY OF NEW MAGNETS IN THE HEUSLER ALLOY FAMILY



Stefano Sanvito
School of Physics and CRANN Institute, Trinity College Dublin, Dublin, Ireland

Magnetic materials underpin modern technologies, ranging from data storage to energy conversion to contact-less sensing. However, the development of a new high-performance magnet is a long and often unpredictable process, and only about two dozen feature in mainstream applications. Here we describe a systematic pathway to the discovery of novel magnetic materials, which demonstrates an unprecedented throughput and discovery speed. Based on an extensive electronic structures library of Heusler alloys containing 236,115 prototypical compounds, we have filtered those alloys displaying magnetic order and established whether they can be fabricated at thermodynamical equilibrium. Specifically, we have carried out a full stability analysis for intermetallic Heuslers made only of transition metals. Among the possible 36,540 prototypes, 248 are found thermodynamically stable but only 20 are magnetic. The magnetic ordering temperature, TC, has then been estimated by a regression calibrated on the experimental TC of about 60 known compounds. As a final valida- tion we have attempted the synthesis of a few of the predicted compounds and produced two new magnets. One, Co2MnTi, displays a remarkably high TC in perfect agreement with the predictions, while the other, Mn2PtPd, is a complex antiferromagnet. Our work paves the way for large-scale design of novel magnetic materials at unprecedented speed.