1989 Volume 30 Issue 12 Pages 973-983
The dissolution at edge dislocation sites on the Cu (111) surface was studied as a function of concentration of inhibitor NH4Br in Young’s etchant. The dissolved thickness S of the matrix surface was measured by two-beam interferometry and the width h and depth d of dislocation etch pits formed were measured by replica electron microscopy. The horizontal dissolved length and the vertical dissolved depth at the dislocation sites, H and D, were determined from S, h and d, respectively.
As the concentration of NH4Br in the etchants increased, H decreased remarkably, and D attained a maximum value at its medium concentration. On the other hand, S was almost unchanged by varying the NH4Br concentration. It was shown that these results could be explained qualitatively on the basis of the two-dimensional nucleation theory of crystal dissolution by considering the variations of the adsorption fraction of poisons, the interfacial energy and the difference in chemical potentials when the concentration of NH4Br was increased.
