A highly porous surface of synthetic monocrystalline diamond: Effect of etching by Fe nanoparticles in hydrogen atmosphere

Abstract We studied the etching of surface of synthetic monocrystalline diamond by Fe nanoparticles. The diamond was grown in the Fe-Ni-C system by high pressure high temperature (HPHT) process. To produce the Fe nanoparticles we used the technique of reduction of ferric chloride by hydrogen. Our experiment demonstrated only a normal type of etching resulted in formation of a highly porous surface on the diamond crystal: such surface consists of numerous channels oriented normally to a surface plane. Different faces of a diamond sample were etched simultaneously. Micromorphology of the etched surface was characterized by atomic-force microscopy. It was shown that after etching the average roughness was 20.8 nm in comparison with the 1.64 nm for the as-grown diamond before treatment. We propose that the highly porous surface obtained by this technique can be used when producing diamond-metal composites or as a catalytic support for fixing of metal micro- and nanoparticles inside the etched channels.