Etching of diamond surfaces with gases

Abstract

Abstract Etching experiments are described in which diamonds showing octahedral, cubic and dodecahedral faces are heated in air within the temperature range of 800°c to 1400°c. A change in the etch pit orientations of the characteristic etch pits for these faces has been found as the temperature of etching is raised. Etching with mixtures of gases has led to the conclusion that oxygen and water vapour are the relevant constituents of air in the formation of well-defined etch pits. Surface graphite formation at temperatures below 1400°c is considered and it is proposed that the mechanism of formation is essentially a chemical reaction and not connected with a purely physical phase change.