Direction specific interactions of 1,4-dicarboxylic acid with calcite surfaces

Interactions of succinic acid (SUC) with the {104} cleavage faces of calcite show a strong preference in crystallographic directions. In situ atomic force microscopy revealed that the morphology of etch pits on the crystal surfaces experienced a transition from the common rhombus to a hexagon upon the introduction of SUC. The pit shape further evolved from 6-sided to 7-sided and eventually to 5-sided with increasing concentrations of SUC. Analysis indicates that the morphology changes may result from SUC preferentially binding to the [42] and [010] edges of the (104) plane to selectively slow down their step speed.