New magnetic materials for electric motors

Rare earth magnets are much stronger than ferrite ones, thus resulting in greater performance for smaller motors. However, rare earth magnets are more expensive given that most reserves are controlled by emerging markets. Currently, the EU faces strong competition from China, which has started to develop its own devices in addition to exporting the raw materials.

In the EU-funded project 'Nanocrystalline permanent magnets based on hybrid metal-ferrites' (NANOPYME), scientists are improving ferrite magnetic properties by synthesising novel hybrid nanocomposites based on metals and metal-ferrite oxides. NANOPYME is combining the complementary magnetic properties of both materials to produce stronger magnets.

The new magnets will boast the advantage of not being sensitive to air exposure, compared to rare earth ones that need to be coated to avoid rapid oxidation.

Competitiveness, safety, recyclability and eco-efficient production will be important parameters to successfully scale-up production from the laboratory to industry.

To prove the potential of the newly developed magnetic materials, NANOPYME will design and test a full-scale prototype motor for an electric bike. This bike has similar requirements to direct-drive wind turbine generators. The project will also develop a protocol for adapting infrastructure and the procedures used in existing manufacturing lines for producing ferrite-based magnets at a minimum cost.

Through computer simulations, scientists have derived the relationship between nanocomposite structural and magnetic parameters. Using a number of methods, project members have synthesised cobalt-ferrite nanoparticles that demonstrated outstanding microstructural and magnetic properties.

Another project achievement has been to grind strontium-ferrite into fine and homogeneous powder for use in magnets. NANOPYME has developed a new process that allows recovery and improvement of the original magnetic properties of the initial strontium-ferrite powder.

Through NANOPYME, Europe will mobilise its resources in a concerted way to take the lead in development of permanent magnets free of rare earth elements. NANOPYME's eco-friendly processing methods will significantly reduce the environmental impact of permanent magnet production.