Ion beam forming of a shell type natural single crystal diamond stylus and sharpening of it by swinging a conical type diamond stylus

Natural single crystal diamond is used as a source material for diamond stylus employed in instruments for surface roughness measurement, and also used as diamond probe for AFMs due to ultra-high strength, ultra-high hardness, very-low friction coefficient, and so on. During the sharpening of diamond tools, facet formations at the tip and ripple formations at the cutting face (or at the tip's face) become problematic. We have successfully employed ion beam processing for the sharpening of diamond tools with small apex angles without any formation of facet or ripples. However, the sharpening conditions are limited to small areas only. Therefore, we introduced a new technique where a sample is swung during ion beam sharpening process to expand the processed area. We applied the technique for sharpening of a conical type diamond stylus and forming of a shell type diamond stylus by 1 keV Ar+ ion beam at the swing angles of ± 60° and ± 90° respectively. Result shows that the facet or ripples were not formed on the processed surface. A simulation method is also developed for predicting the profile changes of diamond tools during ion beam machining at different swing angles.

► Sharpening of a conical type diamond stylus by 1 keV Ar+ ion under swing angle of ± 60° was done.
► We obtained a shell type diamond stylus by 1 keV Ar+ ion under swing angle of ± 90°.
► We saw no facets or ripples on the final surface.
► A simulation was done for predicting the profile changes of diamond tools during ion beam machining at fixed swing angles.