Indexing the hopper shaped {111} face produced in chemical vapor deposited diamond

The hopper shaped {111} face frequently observed in cubo octahedral crystallites of diamond has been analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The diamond was grown via hot filament assisted chemical vapor deposition with a feed gas composition of 1% methane in hydrogen. The SEM images of these crystallites show that the {100} faces are usually flatter than the {111}. The hopper shaped {111} faces have been imaged using the tapping mode of the AFM and the angles between planes and their orientations determined. The planes comprising the hoppered {111} face were found to belong to the {221} and {331} family. The implications of the presence of higher index planes as well as other growth features on the growth mechanisms involved are presented.