Superconductors can sustain persistent currents that allow them to generate magnetic fields many times higher than rare-earth magnets. One way of achieving this is by using commercial high temperature superconducting tape which has micron thin layers of YBa2Cu3O7-x superconductor on metal substrates. Cutting and stacking such tape allows for a superconducting composite permanent magnet (SCPM) to be created. Such an approach has recently been used to generate 13.4 T between two SCPMs of 12 mm size. Methods of magnetising the SCPMs, including with pulsed fields, will be discussed.
The main application in mind for these new types of magnets is on the rotor of electric motors. The current research is for two projects seeking to create a high power density superconducting motor prototype for future electric aircraft. A brief introduction will be given for environmentally friendly electric and hybrid electric aircraft and why superconducting motors are likely essential for them. Advantages of using the SCPMs over competing technologies will be discussed as well as the challenges that need to be overcome such as limiting demagnetisation during motor operation.