Synthesis and characterization of freestanding diamond/carbon nanoflake hybrid films

Freestanding diamond/carbon nanoflake hybrid films have been synthesized by generating variable gas chemistries near a microstructured substrate in a conventional diamond deposition reactor. A multi-cathode direct current plasma enhanced CVD reactor, designed to deposit thick diamond wafers in its conventional configuration, has been used. The deposition conditions are identical to that for diamond films (10%CH4 in H2 gas, 100 Torr, 700–800 °C) except for a novel substrate. A sacrificial layer of silica micro-spheres (diameter 10–30 μm) was close-packed through gentle agitation of the spheres on a 100 mm diameter molybdenum disc. The growth of diamond and graphitic phases was observed on the front and back surfaces of the micro-spheres respectively. TEM observation confirmed that they were chemically bonded hybrid films without any distinguishable interlayer between the two phases.