GROWTH OF META-CHLORONITROBENZENE CRYSTALS IN THE PRESENCE OF TAILOR-MADE ADDITIVES - ASSIGNMENT OF THE POLAR AXES FROM MORPHOLOGICAL-CHANGES

Measured face growth rates of meta-chloronitrobenzene (m-CNB) crystals grown in the presence of para-chloronitrobenzene (p-CNB) confirmed th e previous morphological calculations that p-CNB molecules enter prefe rentially the chlorine-rich end of the polar c-axis of m-CNB crystals, the growth of this end being greatly inhibited. A simple experimental technique is introduced to demonstrate how an absolute assignment of a polar axis in a noncentrosymmetric crystal can be made by the use of the appropriate additives.