On the nature of two-dimensional forms on the polar cleaved surface of triglycinesulfate crystals

The fine structure of the atomically smooth polar (010) surface of a ferroelectric triglycinesulfate crystal has been studied by atomic-force microscopy at room temperature and on heating. The round ledges and holes with nanometric lateral sizes and height (depth) 1/2b (0.63 nm) have been shown to appear only on atomically smooth surface areas when the crystal is cleaved in the ferrophase, and they are the characteristic stable details of its microrelief. They remain unchanged in their geometric sizes upon prolong exposure to air and heating above the Curie temperature, existing regardless of the domain structure and direction of the polarization vector, but they can change under mechanical strains.