ANISOTROPY IN DIAMOND ETCHING WITH MOLTEN CERIUM

An orientation-dependent etching behavior has been observed during dif fusional thinning of single crystal diamond by molten cerium. The etch ing rate at 920 degrees C was in the order of {111}>{100}>{110} with a relative ratio of about 5:2:1. This diamond etching anisotropy is ten tatively attributed to the orientation-dependent difference in the ene rgy required to break the bonds on each atomic plane. It is interestin g to note that the easiest-etching plane found here, {111}, is the mos t difficult plane to polish mechanically, and the most difficult plane to etch; {110}, is the easiest plane for mechanical polishing. (C) 19 94 American Institute of Physics.