Effect of holding time on Pr₆O₁₁ etching diamond single crystal

To study the effect of holding time on the etching of diamond single crystal by Pr₆O₁₁, the mixture of Pr₆O₁₁ and diamond was heated at different holding time in 900 ℃ and N₂ atmosphere to etch the diamond single crystal. The etching effect was characterized by the surface morphology, the etching depth and the single particle compressive strength of the diamond single crystal after etching. The results show that Pr₆O₁₁ can promote the etching of the diamond surface, and the etching degree and the maximum etching depth increase with the increase of holding time. When the holding time is 120 min, the etching pits on the {111} surface and {100} surface of the diamond are stepped inverted pyramid and honeycomb respectively, and the maximum etching depth is 15.07 μm and 4.27 μm. The compressive strength of single diamond particle also decreases with the prolongation of holding time, but the compressive strength of single diamond particle etched by Pr₆O₁₁ is higher than that of diamond etched without adding etchant and directly etched in air.