Homoepitaxial Diamond Grown in a Liquid Metal Solvent

A single-crystal diamond substrate (SCDS) with a (100) surface orientation was submerged in liquid gallium containing a small amount of dissolved silicon, and exposed to a mixture of methane and hydrogen at 1 atm and 900 ºC. New growth diamonds were found that are single crystal square pyramids with (111) facets and that are homoepitaxial to the substrate, as proven by scanning and transmission electron microscopy, and small angle X-ray scattering and diffraction. Raman spectroscopy with 13C-labeling prove that the methane as well as the SCDS are the carbon source for the newly grown diamond. This approach opens up new ways for growing diamond in liquid metal systems.