Electrical properties of aggregated detonation nanodiamonds

Nanometer-scale diamonds formed using a detonation process are an interesting class of diamond materials. Commercially supplied material is highly aggregated with similar to 5 nm diamond crystals forming particles with micron sizes. Previous models have suggested that nondiamond carbon is incorporated between the crystals, which would reduce the electrical and chemical usefulness of this form of diamond. However, using impedance spectroscopy we have shown that at temperatures below 350 degrees C the form of detonation nanodiamond being studied is a near to ideal dielectric, implying a full sp(3) form. At temperatures above this the surfaces of the diamond crystals may support some nondiamond carbon. (C) 2008 American Institute of Physics.