An international collaboration led by Prof Stefano Sanvito Investigator in AMBER, the Science Foundation Ireland funded materials science centre based at Trinity College Dublin, has identified 22 new magnets in the last year. This rate of discovery is 20 times faster than that achieved in the last 2,000 years, in which time we have discovered about 2,000 magnetic materials, or one per year. Their method of using advanced computer simulations enabled them to predict the chemical composition of new magnets and their findings have been published today in the prestigious journal, Science Advances.*
Since the invention of the compass, magnetic materials have been key for the development of every-day technologies: the hard disks of our computers are composed of billions of tiny magnets; wind turbines are made from strong permanent magnets; as are the electrical motor in our cars, kitchen blenders and lawn mowers. Current high-performing magnets are made of expensive elements (e.g. rare earths) and their price is very volatile. This is a central reason for the need to continue to identify new magnetic materials - avoiding the risk of supply collapse. In addition to this, the process of discovering new magnets can be lengthy. The first report of a magnetic material dates back to 79AD. In all this time, we have discovered about 2,000 materials, which behave as magnets, or one magnet per year.
This research provides a path for the fast discovery of new advanced materials. Rather than have experimentalists working in the lab trying to make approximately 300,000 new hypothetical materials, Prof Sanvito’s team can use computer simulations combined with powerful databases to predict the properties of these 300,000 materials and then advise which ones are likely to work best for particular applications. They can recommend materials that might be best suited to solar applications, or for thermo-electrics, anti-corrosive or aerospace materials design.
Prof Sanvito, Director of the CRANN Institute and Investigator in AMBER and Trinity’s School of Physics said, “The discovery of new magnets is important because they form part of everyday applications, from computers, to wind turbines, the electrical motors in our cars, kitchen blenders and lawn mowers. However, there are several technologies for which we still need to find the ideal magnet, which could provide for example more energy-efficient non-volatile magnetic storage, such as hard discs and more energy efficient motors in hybrid cars.”
In this publication, our team identified 22 new magnets, and one in particular, Co2MnTi, shows real potential for high-tech applications because it displays a very high ordering temperature of about 630 degrees Celsius (a magnet loses its magnetic properties above the ordering temperature). This is a remarkable discovery since no more than two dozen magnets remain magnetic at such a high temperature. The ordering temperature should be well more than the temperature at which you want to use the magnet, for example, if the magnet is to be used in an electrical motor in a hybrid car, it must be magnetic at the temperature of the engine about 200C.
The multi-disciplinary team included the groups of Prof. Michael Coey, also an AMBER Investigator who made two of the new magnets and Prof. Curtarolo at Duke University, who was involved in the theoretical work.
* Accelerated discovery of new magnets in the Heusler alloy family, Science Advances, 14th April 2017