Microwave Conductivity of Boron-Doped Nanodiamond Particles

Boron doped diamond particles (BDDP) have been investigated using dielectric spectroscopy from 100 Hz to 10 GHz using a combination of microwave cavity perturbation and the broadband coaxial probe method. Raman and x-ray photoelectron spectroscopy demonstrate that the BDDP consist of both diamond and a considerable concentration of non-diamond carbon. The electrical conductivity increases with the boron to carbon (B/C) ratio in the fabrication process. The microwave complex permittivity also increases with increasing B/C ratio from, with loss tangent increasing from 0.4 to as large as unity, demonstrating the potential for BDDP in tuneable microwave absorber additives.