Accelerated discovery of new magnets in the Heusler alloy family

As a final validation, we attempted the synthesis of a few of the predicted compounds and produced two new magnets: Co2MnTi, which displays a remarkably high TC in perfect agreement with the predictions, and Mn2PtPd, which is an antiferromagnet.

A useful magnet, regardless of the particular technology, should operate in the −50° to +120°C range, imposing the ordering temperature, TC, to be at least 300°C. Specific technologies set additional constraints. Permanent magnets should display large magnetization and hysteresis (3). Magnetic electrodes in high-performance tunnel junctions should grow epitaxially on a convenient insulator and have a band structure suitable for spin filtering (4). If the same tunnel junction is used as spin-transfer torque magnetic memory element, then the magnet should also have a low Gilbert damping coefficient and a high Fermi-level spin polarization (4). There are not many magnets matching all the criteria; hence, the design of a new magnet suitable for a target application is a complex and multifaceted task.

... often a high-temperature magnet may represent a singularity in physical/chemical trends and that its search can defy intuition. For this reason, we take a completely different approach to the discovery process