Study of the Dissolution of the Barium Sulfate (001) Surface with Hydrochloric Acid by Atomic Force Microscopy.
Noncontact atomic force microscopy (NC-AFM) has been used to investigate the morphological changes of a freshly cleaved (001) surface of barium sulfate (barite) etched with an aqueous solution of 0.1 M HCl at room temperature. Shallow triangular etch pits with a height of 3.6 Å were developed in atomically flat (001) terraces. The etching of the surface was found to proceed in a layer-by-layer dissolution process. Because the crystal structure of barite exhibits a two-fold screw axis parallel to the c axis, "alternating" etch pits were formed, with any two consecutive etch pits pointing opposite to each other. These etch pits became deeper and more elongated along the b axis with time. Copyright 1999 Academic Press.
Wang
KS
Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California, 90089
Resch
R
Koel
BE
Shuler
PJ
Tang
Y
Chen
Hj
Yen
TF