Morphology evolution and mechanism exploration of the diamond surfaces etched by La2O3 powder

In order to systematically study the morphology evolution and mechanism exploration for the diamond surfaces etched by La2O3 powder in N2, the surface morphology, surface roughness, crystal structure, and etched mechanism were investigated. The results reveal that diamond surfaces can be effectively etched by La2O3 from 820 °C to 980 °C, and the etching process is anisotropic. The intensity of the etching increases as the temperature rises. Because of the various carbon atom configurations on the diamond surfaces, the etched pits' morphologies on the {111} surface are an inverted triangular prism and those on the {100} surface are an inverted pyramid. The Ra value of {100} plane increases from 0.40 μm to 2.28 μm, whereas that on {111} one increases from 0.70 μm to 3.32 μm. Furthermore, the mechanism of the diamond surfaces etched by La2O3 is the graphitization process of the diamond.