High-frequency electrical transport in nitrogen incorporated nano-crystalline diamond films in the GHz regime
1 Nano-Scale Transport Physics Laboratory, School of Physics and DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand - Private Bag 3, WITS 2050, Johannesburg, South Africa
2 Raman and Luminescence Laboratory, School of Physics, University of the Witwatersrand - Private Bag 3, WITS 2050, Johannesburg, South Africa
Received: 28 October 2014
Accepted: 5 March 2015
Measurement of alternating current conductance in the gigahertz regime of free standing nitrogen incorporated nano-diamond films is reported. Using a simple and newly developed technique, the scattering parameters of the nanodiamond films were measured on coplanar waveguides. The conductance is evident as a crossover from insulating behaviour where to the metallic regime where . From the micro-Raman studies of the films we conclude that this crossover is due to the changes in the grain boundary morphology which is driven by the level of nitrogen during synthesis. These results are in agreement with previous direct current measurements.
PACS: 73.63.Bd – Nanocrystalline materials / 72.30.+q – High-frequency effects; plasma effects / 72.80.Ng – Disordered solids
© EPLA, 2015