Investigation on the doping capability of the divalent cations on the KDP crystal

The aim of this paper is to investigate the factors affecting the ability of cations as impurity to incorporate the KDP crystal. KH2PO4 powder (AR) and deioned water (resistivity greater than or equal 18.2MΩ·cm) were used as raw materials, BaCl2·2H2O, CuCl2·2H2O and MgCl2·6H2O were doped respectively. The results show that the content of Cu2+ and Mg2+ in the crystal basically keep constant and doesn't increase with the increasing of that in the solution, and the content of Cu2+ in the crystal is larger than that of Mg2+ in the crystal. However, the content of Ba2+ in the crystal increases with the increasing content of Ba2+ in the solution. It can be deduced from the experimental results that both the ionic radius and the dehydration heat are the important factors affecting the ability of the divalent cations to incorporate the KDP in the process of crystal growth from solution.