Researchers across the globe are discovering effects and materials that could cut the cost of high-strength magnets.
In a $31.6m programme called REACT (Rare Earth Alternatives in Critical Technologies for Energy), the US government has set its universities the task of sorting the wheat from the chaff, aiming to cut its dependency on the rare earths samarium and neodymium - which it has to import from China.
Many of the potential alternatives to rare earth magnets are purely theoretical, or use effects only observed in tiny points within crystals.
Much of the funded research is described as having a high risk of failure, and much of it involves nano particles.
REACT's aim is to deliver bulk magnetic materials suitable for electric motors and generators within electric vehicles and wind turbines, form readily-available minerals.
Iron and nitrogen are freely available, and certain iron nitride crystals are amongst the most powerful magnets ever measured, but only in tiny structures.
Case Western University will attempt to add small amounts of other metals to iron nitride to stabilise the material . "This magnet could have the highest energy density made entirely from earth abundant raw materials," claimed the University, which aims to build a prototype electric motor.
The University of Minnesota and Oak Ridge National Laboratory form a separate team attempting to synthesise and phase stabilise iron nitride - in its body centre tetragonal meta-stable form, within an anisotropic nano-composite to form a prototype bulk magnet.
Oak Ridge National Laboratory and the University of Minnesota are investigating an iron nitride in the 'alpha double prime' phase which looks to exhibit the highest saturation magnetisation ever. If the material's meta-stability and easy demagnetisation can be cured, wind turbines could be cheaper.
There is nothing sacred about rare earth elements, said ORNL researcher David Parker. "Their main advantage is that due to their large nuclear charge, spin-orbit coupling is very strong and serves to fix the magnetization direction of the unpaired electrons. Other heavy elements may play the same role."
According to ORNL, a 3MW wind turbine contains 250kg of magnetic materials.
Nano-crystalline MnAl will be studied at Dartmouth College with the aim of developing a process to make bulk nano-crystalline manganese-aluminium alloys.
Two of the most traditional of permanent magnet metals, iron and nickel, will be studied by a consortium led by Northeastern University intending to create "bulk quantities of iron and nickel in a unique crystal structure with powerful magnetic properties".
According to Northeastern, the particular structure is found naturally in meteorites that formed over millions of years. The team aims to artificially create the material, and find a way to stabilise the structure in bulk by adding other elements.
Other consortium members are: Arnold Magnetic Technologies, Columbia
University, General Motors R&D, University of Massachusetts Amherst, University of Nebraska Lincoln.
Manganese is at the centre of a programme from Pacific Northwest National Laboratory which intends to build manganese composite magnets with 40MGOe (mega(gauss-oersteds)) energy density at 200°C.
Supercomputer modelling and synthesis experiments will be employed by the team, which includes: Ames Laboratory, Electron Energy, United Technologies Research Centre, University of Maryland, University of Texas at Arlington.
Manganese bismuth and M-type hexaferrite in their hexagonally symmetrical forms (where M represents barium, strontium or lead) will be studied by the University of Alabama, University of California at San Diego, and Mississippi State University with the aim of demonstrating magnetic properties in a bulk magnet with these two material systems.
100nm particles embedded in a matrix forming a nano-composite will form the basis of 'exchange-spring' magnets at Argonne National Laboratory - working with Electron Energy Corp.
Exchange-spring magnets combine two types of ferromagnetic particle, one hard magnetic and one soft magnetic to provide a high coercive field and high saturation respectively.
Most of the nano-composite projects in the REACT list are attempts to do something similar with different materials.
Transition metal carbides in composites are the subject of research at Virginia Commonwealth University, working with Arnold Magnetic Technologies, Northeastern University, Brookhaven National Laboratory, and University of California San Diego, Moog and Bayer Technology Services.
The element cerium is at the centre of a project by Ames Laboratory, General Motors, Molycorp and NovaTorque.
"Cerium is four times more abundant than the critical rare earth element neodymium," said Ames. "This project is looking at combining other
metal elements with cerium to create a magnet that has the high temperature stability required for electric vehicle motors."
Rather than permanent magnets, some effort is going into superconducting coils to produce static magnetic fields.
The University of Houston is leading a consortium that will study "a new, low-cost superconducting wire", specifically for employment in wind generators.
Other consortium members are the US National Renewable Energy Laboratory, SuperPower, Tai-Yang Research and TECO-Westinghouse
Motor Company.
Brookhaven National Laboratory and partner American Superconductor have a separate project with a similar aim - to develop a low-cost superconducting wire - this time for direct-drive (no gearbox) wind turbines.
Completely shifting away from magnets, General Atomics and the University of Texas at Dallas will develop a 'double stator' switched reluctance motor.
Switched reluctance motors do not use the attraction or repulsion of magnets, but the attraction of unmagnetised iron by electromagnets. The double stator design, invented at Dallas, makes better use of magnetic force to increasing torque.
On the application side, a team of QM Power, Oak Ridge National Laboratory, Smith Electric Vehicles and the University of Delaware will build a motor for electric vehicles using unspecified "emerging materials and advanced manufacturing techniques".
Another application project, this one centred around a motor with a unique cooling system, comes from Baldor Electric and Arnold Magnetic Technologies.