Possibilities of Predicting the Structural Phase of a Future Crystal Based on the Determination of the Types of Nanoscale Clusters of a Saturated Solution Using the Example of KD2PO4. Part 2: Determination of the Relationship between the Types of Precursor Clusters and the Structural Type of Grown Crystals

A correlation has been established between the type of precursor cluster in KD2PO4 crystallization solution and the crystal phase formed in this solution. Based on the areas of precursor cluster formation established in saturated crystallization KD2PO4 solutions in Part 1, the characteristic types of solutions were prepared, in which the following clusters were formed: octamers only, tetramers only, and a mixture of octamers and tetramers. Crystallization was carried out in these solutions under the conditions specified in Part 1. It has been established that the formation of octamers at low temperatures leads to the growth of crystals of the tetragonal phase (I 4 2d), whereas the formation of tetramers at high temperatures leads to the appearance of crystals of the monoclinic phase (P21) ; under conditions of coexistence of tetramers and octamers, crystals of both phases grow.