Premium
Properties of Surface Layers in Single Crystals of Calomel
Author(s) -
Barta Č.,
Brožek V.,
H´jek B.,
Barta Č.
Publication year - 1982
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170170408
Subject(s) - etching (microfabrication) , materials science , surface layer , layer (electronics) , cleavage (geology) , residual stress , single crystal , isotropic etching , crystallography , crystal (programming language) , analytical chemistry (journal) , chemistry , composite material , mineralogy , chromatography , fracture (geology) , computer science , programming language
Within the framework of the systematic study of differences in physical properties of the calomel (Hg 2 Cl 2 ) single crystals before and after surface treatment, the differences in the microhardness, the residual stress in the surface layer, and the chemical etching rate were investigated on the (110) and (001) crystal faces. It has turned out that Beilby layer (B‐layer) formed during surface treatment is softer, and, on the cleavage surface is harder than the underlying bulk material. The thickness of the B‐layer in these samples ranged between 5 anf 7 m̈m. Further it has been found that a tensile residual stress s̀ = 14 Nm ‐2 prevails in the surface layer of a polished (110) face to a depth of 70 m̈m and, after grinding, to a depth from 90 to 200 m̈m. On the other hand, a compressive stress has been found in the natural cleavage plane. Experiments on etching the Hg 2 Cl 2 crystals with HCl + HNO 3 etching solution have shown that the rate of chemical etching is 2 to 4 times larger on the (110) face than on the (001) face. Differences are very strongly dependent on the experimental conditions and on the real structure of a given surface.