In Situ Surface Imaging Through a Transparent Diamond Tip

A new approach to the design of transparent diamond indenters is proposed, which allows one to obtain a full optical image of the investigated area of the sample surface, including images directly during measurements by applying the indentation and scratching methods. In this case, it is not required to use immersion liquids that fill the region between the sample and the indenter. The measured area is observed with an optical microscope with illumination through an objective lens. Using an indenter in the form of a trihedral Berkovich pyramid, images of the surface of a test structure and the residual indentation are reconstructed and an image of the surface during its deformation under the application of a load to the indenter is obtained.