Effect of RE³⁺ on Structural Evolution of Rare-Earth Carbonates Synthesized by Facile Hydrothermal Treatment

Figure 4

Diffraction patterns of samples hydrothermally treated for 16 h. (a) Rare earths with a lower atomic number: Ce-based sample (A); Nd-based sample (B); Sm-based sample (C); Sm- (20%-) cerium- (80%-) based sample (D). (b) Rare earths with a higher atomic number: Gd-based sample (E), Dy-based sample (F), Ho-based sample (G), Er-based sample (H), and Yb-based sample (I). The inset reports a magnification of the most intense XRD peak of the tengerite-type structure present in different samples. The main XRD peaks are labelled with H for hexagonal RECO₃OH, O for orthorhombic RECO₃OH, and T for the tengerite-type RE₂(CO₃)₃·2H₂O.

(a)

(b)