Study On Etching Of Diamond Single Crystal By Transition Metal Oxides

Diamond has excellent physical and chemical properties,such as strength,hardness,wear resistance,thermal conductivity,chemical stability and so on.It has been widely used in the field of machine tool manufacturing,but the smooth surface of diamond is not conducive to the control of binder on it.It often exists in the bond is not firm,so that it falls off prematurely and so on.in order to solve this problem,the surface roughness can be increased by surface etching,and the performance can be improved.At the same time,diamond also has a broad application space in semiconductor device manufacturing,thermal management materials and other fields,but the shortcomings of diamond difficult to process restrict the full play of its excellent properties.Therefore,the study of diamond single crystal surface etching technology is also helpful to promote the application of diamond in the field of functional materials.In this paper,diamond single crystal is taken as the research object,and three kinds of transition metal oxides,iron oxide,manganese dioxide and nickel oxide,are used as etching agents,and the surface etching method of diamond single crystal without special atmosphere is explored.The effect of etching process parameters on diamond single crystal was also studied.The main findings are as follows:(1)Diamond can be etched by three transition metal oxides,namely ferric oxide,manganese dioxide and nickel oxide.The optimum temperature for etching diamond by ferric oxide is 800 ?.After etching at this temperature for 1 hour,the surface roughness Sa of {100}surface of diamond increases to 2380 nm,and that of {111} surface to 1590 nm.The optimum temperature for diamond etching by manganese dioxide is 750 ?.After etching at this temperature for 1 hour,the {100} surface roughness Sa of diamond increases to 1188 nm,and the {111} surface roughness Sa increases to 3771 nm.The optimum temperature for diamond etching by nickel oxide is 750 ?.After etching at this temperature for 1 hour,the surface roughness Sa of diamond {100} surface increases to 1775 nm,and the surface roughness Sa of diamond {111} surface increases to 1917 nm.(2)The etching degree of diamond increases with the increase of temperature and holding time.The larger the roughness of diamond surface,the higher the area and depth of etching pits,and the lower the compressive strength of diamond particles.Increasing etching temperature can etch diamond more effectively than prolonging holding time.(3)Diamond etching is anisotropic,The {100} surface etch pits are quadrilateral or octagonal,The {111} surface etching pits are triangular.The difference of etching pit shape is related to the arrangement of carbon atoms in diamond.The etching behaviors of differentetchants are different,the {100} surface of diamond is mainly etched by ferric oxide etchant,the {111} surface of diamond is mainly etched by manganese dioxide etchant,and the surface of diamond is protruded by nickel oxide etchant.(4)Transition metal oxide etching diamond is essentially the oxidation process of diamond under the catalysis of transition metal oxide.