Extreme synthesis and chemical doping of diamond aerogel

Amorphous carbon aerogels have attracted much interest in recent years due to their low density, large intrinsic surface areas ($>$1000 m$^{2}$/g), large pore volume, low dielectric constant, and high strength. We use high-pressure ($\sim $20 GPa) laser-heating ($>$600\r{ }C) within a diamond anvil cell (DAC) to convert the amorphous network of a low-density (40mg/cc) carbon aerogel into an ultrananocrystalline diamond aerogel. Photoluminescence spectroscopy and confocal time-correlated single-photon counting indicate the recovered material contains both negatively-charged and neutral nitrogen-vacancy (NV) complexes. Synchrotron scanning transmission x-ray microscopy (STXM) is used to compare the carbon electronic density-of-states of the amorphous starting material with the recovered diamond aerogel with $\sim $100 meV energy resolution. Finally, we use nanoscale secondary ion mass spectrometry to investigate doping of the resorcinol-formaldehyde starting material with the aim of chemically tuning heteroatomic point defects within this diamond material system.