Condensed Matter Physics Seminar

Dr Oliver Williams, Cardiff Diamond Foundry, School of Physics and Astronomy, Cardiff University

Thursday 27 February 2014, 1600-1700
C1 Physics Building

Nanodiamond Films and Particles

Nanodiamond films exhibit many of the extreme properties of bulk diamond but in a wafer scale package over much larger areas and at significantly reduced cost. Nanodiamond film properties such as Young?s Modulus, Coefficient of Friction and wear resistance are identical to those of single crystal diamond and in some cases enhanced by nano-crystallinity. Properties that involve carrier or phonon transport are obviously degraded by grain boundary scattering and thus carrier mobility and thermal conductivity are a function of grain size in nanodiamond films. Electrical conductivity in nanodiamond films can be controlled from insulating (>1012 ?cm) through semiconducting to pseudo-metallic and even superconducting at low temperatures. Nanodiamond films have applications as diverse as a Micro-Electro-Mechanical Systems (MEMS), heat spreaders, bio-sensors and electro-chemical electrodes.

Nanodiamond particles are fundamental low dimensional diamonds with extreme surface to volume fractions, as high as 400m2/g. This surface to volume fraction has a profound effect on the properties of these particles, with 20% of the carbon atoms residing at the surface. The reactivity of these particles differs substantially for bulk diamond and considerable effort is required to disperse them from their aggregated commercial source. Their applications are as diverse as the seeds for diamond film growth through drug delivery to single photon sources.

This talk will aim to review some of the technology and processes involved in utilising nanodiamond films and particles for real world applications.