Layer-by-layer etching of HgI2 films and crystals by scanning force microscopy

Abstract

Thin films and single crystals of mercuric iodide (α-HgI2) have been investigated by scanning force microscopy. During the scan process, material evaporation is observed proceeding by hole formation and etching at steps. The ratio of etched volume per second and per interaction area between tip and mercuric iodide step edges is found to be constant for hole formation on an HgI2 crystal and for etching at a screw dislocation on HgI2 films. An estimate for the loading of the SFM tip gives a value comparable to the critical resolved shear stress in this material.

Nanomechanical properties of molecular organic thin films

“…The material expelled by the penetrating tip most probably evaporates during the subsequent scan process of image acquisition even if lateral forces are minimized, as is the case of the tapping scanning mode. 21 No indentation-induced dislocations are observed in the vicinity of the indented region. Figure 3͑a͒ shows a nanoindentation curve (kϳ3 Nm Ϫ1 ) performed on an as-grown ␣-p-NPNN thin film.…”