Investigation of the KNd(SO4)2H2O-SrSO40.5H2O System

The cocrystallization of potassium, neodymium, and strontium sulfates from aqueous solutions has been studied using X-ray powder diffraction, thermogravimetry, energy-dispersive X-ray spectral analysis, and electron microscopy. Extensive solid solutions based on trigonal KNd(SO4)(2)& sdot;H2O have been found to exist in the concentration range 100-20 mol % of the KNd(SO4)(2)& sdot;H2O-SrSO4 & sdot;0.5H(2)O system. The unit cell parameters of the solid solutions have been determined. Two phases have been discovered: trigonal KNd(SO4)(2)& sdot;H2O (space group P3(1)21) and monoclinic KNd(SO4)(2)& sdot;H2O (space group P2(1)/c(1)). The heterovalent substitution scheme 2Sr(2+) -> K+ + Nd3+ stabilizes the structure of solid solutions based on the isostructural KNd(SO4)(2)& sdot;H2O and SrSO4 & sdot;0.5H(2)O trigonal phases.

Automated summary

This study investigates the cocrystallization of potassium, neodymium, and strontium sulfates from aqueous solutions. Extensive solid solutions based on KNd(SO4)(2)·H2O and SrSO4·0.5H2O trigonal phases have been found within a certain concentration range.