ATOMIC-FORCE MICROSCOPY OF COATED GLASSES

Atomic force microscopy has been used to investigate the topology of a lkoxide gel dip coatings on different substrates. Results of SiO2 - Ti O2 - ZrO2 (STZ) coatings are presented on float glass, on polished fus ed silica, on commercially coated insulating flat glass, and on PtRh. Consolidated STZ coatings display the so-called glass pattern with rip ples equal or less than 2 nm high. The same pattern is seen on partial ly dense STZ coatings, as soon as the surface is stiff enough for scan ning, and also on the bottom of a 50 nm deep sputtering crater in the consolidated coating. The vitreous STZ coating on the fire side of the float glass is as flat as the float glass itself. It has the same ten dency to contamination. 100 nm wide and 50 nm deep polishing grooves o n fused silica have been filled up with the 80 nm thick coating, only dips of a few nm remain. The trenches between the SnO2 crystallites on the insulating flat glass were filled up and the roughness of the sub strate was partially reduced. PtRh sheet remained rough even after the coating. On the partially densified STZ coating, sputtering generates a grained surface.