Rapid population growth and societal developments are placing increasing stress on the environment and have led to intensified demands for the realisation of new technologies. A pressing example is the threat from climate change. While this issue can in part be tackled by adopting renewable energy sources (e.g. offshore windfarms), these are often remote with heavy losses in energy during transmission. This problem can be addressed by implementing 2^nd generation high temperature superconducting (2G-HTS) tapes for power transmission. However, maximising the current-carrying capacity of these requires optimisation of defect densities for the pinning of magnetic vortices without degrading the critical temperature below which the tapes operate.

More often than not, advances in such technologies have emerged alongside the development of superior measurement and sensing instrumentation. Working with partners Nanomagnetic Instruments Ltd, this project seeks to exploit the benefits of the novel materials, graphene and h-BN, to produce advanced Hall sensors to be incorporated in scanning probe microscopes. These can be used to accurately map magnetic fields and characterise current flows around microscopic material defects with resolution down to the nanoscale. The encapsulation of graphene in h-BN boosts the sensor’s capabilities by greatly increasing the carrier mobility and reducing unwanted 1/f noise for maximum signal-to-noise ratios. In the course of this project, these new scanning Hall probes will be exploited to drive forward the optimisation of the aforementioned 2G-HTS tapes, working together with tape manufacturers from China (Shanghai Superconductor) and the USA (AMSC).

Additionally, the project aims to develop sensors for susceptometry by integrating them with microscopic magnetic field coils. These can be implemented in the process control of additive manufacturing systems, for instance, to map defects in manufactured samples. We will work with partners Renishaw, who are interested in monitoring their metal powder bed fusion technologies. The same approach can also be used in other industries/sectors, for example in the routine characterisation of ferromagnetic data storage media.