화학공학소재연구정보센터
Chemical Engineering & Technology, Vol.38, No.6, 1011-1016, 2015
Growth Rate Dispersion at the Single-Crystal Level
Evidence of growth rate dispersion for symmetry-related opposite faces of centro-symmetric single crystals of ammonium perchlorate is provided. Crystallization experiments conducted by evaporation of a stagnant aqueous solution at room temperature show that some (hkl) faces have high and irregular normal growth rates, in time and space, whereas the corresponding ((h) over bar(k) over bar(l) over bar) faces crystallize slowly and steadily. The (hkl) faces presenting high and irregular crystal growth also form repetitive inclusions, whereas ((h) over bar(k) over bar(l) over bar) 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.