Growth Rate Dispersion at the Single‐Crystal Level

Abstract

AbstractEvidence of growth rate dispersion for symmetry‐related opposite faces of centrosymmetric single crystals of ammonium perchlorate is provided. Crystallization experiments conducted by evaporation of a stagnant aqueous solution at room temperature show that some $ ({\rm{hkl}}) $ faces have high and irregular normal growth rates, in time and space, whereas the corresponding $ ({\rm{\overline h}}\;{\rm{\overline k}}\;{\rm{\overline l}}) $ faces crystallize slowly and steadily. The $ ({\rm{hkl}}) $ faces presenting high and irregular crystal growth also form repetitive inclusions, whereas $ ({\rm{\overline h \;\overline k \; \overline l}}) $ faces are not involved in any formation of vacuoles. As a consequence, it is possible to retrace the crystallization history of a single crystal by analyzing the location of series of inclusions showing the progressive displacement of its center of gravity.