Correlation of the pit depth in crystal etching by dissolution

A theoretically rigorous formulation relating the pit depth to dissolution time for crystal etching is presented and verified. The data of K, Dunn, E. Daniel, P. J. Shuler, H. J, Chen, Y. Tang, and T. E Yen [J. Colloid Interface Sci. 214, 427 (1999)] for surface dissolution of barite are analyzed and correlated accurately. It is shown that the empirically determined power law pit growth function of E Hunkeler and H. Bohni [Corrosion, 37(11), 645 (1981)] conforms to a special solution of the present formulation and their empirically determined power law exponent of 1/2 is theoretically justified. In addition, the present study provides some insight into the mechanism of the crystal dissolution rate process and the variation of pit depth during dissolution-induced etching. (C) 2000 Academic Press.