Transport Properties of Boron-Doped Nanocrystalline Diamond (BNCD)

The research is focussed on the properties of superconducting boron-doped nanocrystalline diamond (BNCD) films.
The BNCD system is a highly tuneable system, where the electron carrier concentration can be controlled by the level
of boron doping, allowing a transition from insulating to superconducting behaviour. The material is granular, with the
size of the grains depending on the film thickness and details of the deposition process. We are currently developing the
theory for the increase in electrical conductivity close to the superconducting transition temperature (the fluctuation
conductivity). Experimentally this shows three distinct regions with different power law behaviours, which is believed
to be due to the size of the Cooper pair relative to that of a typical grain. We have currently calculated all the contributions
to the fluctuation conductivity, and are trying to reconcile them with the experimental data from our collaborators in Cardiff.
Detailed fitting will hopefully provide a method for extracting various material parameters of BNCD and other granular
superconducting systems.