Precipitation of image and image compounds from aqueous solutions for image and image

Double carbonates of lanthanide (Ln) and alkaline or ammonium (A) ions, noted image, were precipitated from concentrated image aqueous solutions at room temperature and atmospheric pressure. Twelve hydrated compounds out of the twenty targeted ones have been obtained: image, image, image, image, image, image from concentrated image solutions and image from concentrated image solutions. Although the trivalent lanthanide ions are often considered as analogs in solution, differences in their precipitation behaviour was observed, which is believed to have a kinetic origin in relation to the small differences in their ionic radii. The solid compounds were characterised by elemental analyses, thermogravimetry (TG), X-ray diffraction (XRD) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The powder diffraction patterns of nine solids were fitted using the tetragonal image class: image: image, image, image: image, image, image: image, image, image: image, image, image: image, image for image: image and image, where image is the ionic radius of image for a coordination number of 8 (image, image, image and image). It is proposed that all the image compounds are of very similar structure, as evidenced by their XRD patterns and by the linear variations of the lattice parameters with image. The small differences in the lattice parameters can induce large modification of the precipitation pathways. Conversely, structural changes were evidenced within the image series for image. image was also obtained as a by-product. Its lattice parameters are in good agreement with image ones.