Surface structure of hydrated amorphous silicon oxide at 3 Å resolution by scanning force microscopy

The topology of a fully hydrated amorphous silicon oxide surface was studied with a scanning force microscope. The structure of the surface could be resolved down to 0.3 nm. The autocorrelation function of the surface relief exhibited no long range periodicity and had a glasslike character with a next neighboring repeat distance of 0.4–0.5 nm. The correlation between images obtained simultaneously from forward and backward scans was high and therefore showed that the measured surface reliefs are to a large extent independent from the local tip shape. The pair-correlation functions of subsequent images of the same surface area, however, revealed a decay over several minutes which indicates that a rearrangement of the surface may occur.