Influence of SiO₃^2‐ impurity on growth habit of potassium dihydrogen phosphate crystal

Abstract

By altering the concentration of silicate (SiO 3 2-) impurity in the solution, a series of potassium dihydrogen phosphate (KDP) crystals was obtained by the conventional temperature cooling and the rapid growth methods, respectively. It was observed that the presence of SiO 3 2-made KDP crystals tapering in conventional cooling method, while more SiO 3 2-induced inclusions at prismatic sectors in the rapid growth method. Laser-polarization-interference results showed that SiO 3 2-extended the dead zone and reduced the growth rate of (100) face of KDP crystals. The negative influence of SiO 3 2-on the growth was considered absolutely similar to the effect of cations. It was also suggested that the stability of solution doped with SiO 3 2-was improved without seed crystals, while it was destructed with seed crystals. The inhibition mechanism was analyzed in terms of SiO 3 2-absorption on (100) face.

Model Development and Experimental Validation for Crystal Shape Control by Using Tailored Mixtures of Crystal Growth Modifiers

“…In situ images were captured by using a PVM probe and were analysed based on blob analysis in the PVM Image Acquisition and Lasentec PVM Stat Acquisition software in order to extract information of crystal shape distribution ( Figure 1). The different facets of the crystal exhibit different charges because of the internal structure (Ding et al, 2010) as it can be seen on Figure 2. Table 1 shows the used amounts of CGMs in all experiments.…”

“…Crystals captured by PVM and detected particles by using image analysis software Molecular arrangement and morphology of KDP crystal(Ding et al, 2010) …”

Multi-Impurity Adsorption Model for Modeling Crystal Purity and Shape Evolution during Crystallization Processes in Impure Media

“…The effect of growth modifiers on the shape is closely linked to the molecular arrangement in the crystal lattice. Often different crystal faces exhibit different charges hence impurities with positive or negative charges will adsorb preferentially on different faces of the crystal 16,24,27,[54][55][56][57][75][76][77][78] . In the case of the current work, divalent and trivalent metal ions preferably adsorb on the {100} face of KDP crystal, which leads to decreased growth rate of the corresponding characteristic length.…”