Syntheses and Crystal Structures of the Compounds Na Ln TiO 4 ( Ln = La, Pr, Nd)

Single crystals of the Na Ln TiO 4 ( Ln = La, Pr, Nd) phases were grown out of reactive sodium hydroxide melts. These layered materials crystallize in space group P 4/ nmm of the tetragonal system, with unit cell dimensions of a = 3.7998(5) Å and c = 13.273(3) Å (La), a = 3.7686(5) Å and c = 12.940(3) Å (Pr), and a = 3.7551(5) Å and c = 12.848(3) Å (Nd). These compounds possess a layered structure that is a variant of K 2 NiF 4 with ordering of the Na and Ln ions. Graphical Abstract The compounds Na Ln TiO 4 ( Ln = La, Pr, Nd) were grown as single crystals from a reactive sodium hydroxide flux, and the structures were solved by single-crystal X-ray diffraction. The crystal structure of Na Ln TiO 4 , as viewed along [010] is shown. with TiO 6 octahedra in blue, Ln 3+ cations as green spheres, Na + cations as orange spheres, and O 2− anions as red spheres.