Synthesis and Crystal Structure of the Layered Lanthanide Oxychlorides Ba₃Ln₂O₅Cl₂

Abstract

Single crystals of a new family of layered lanthanide oxychlorides, BaLnOCl (Ln = Gd-Lu), have been synthesized from a molten barium flux. This family crystallizes in the space group I4/mmm (No. 139; Z = 2) with lattice parameters a = 4.3384(1)-4.4541(1) Å and c = 24.5108(7)-24.8448(9) Å. BaLnOCl phases are built up of two different blocks: a perovskite double layer of stoichiometry BaLnO formed by corner-connected LnO tetragonal bipyramids and a puckered rock-salt-like interlayer of composition BaCl. A complete structural study along with bond-valence-sum calculations shows that, for lanthanides larger than gadolinium, the structure becomes unstable. Density functional theory calculations show that the valence-band edge is dominated by oxygen orbitals, whereas the conduction band forms from Ba 5d orbitals. The synthesis of this family suggests a route to other potential multianion phases.

Recent Developments on Molten Salt Synthesis of Inorganic Nanomaterials: A Review

“…The MSS has proven to be an efficient approach for achieving complex nanosized M-O-X-type oxyhalides. , Specifically, oxyhalides such as Bi 4 TaO 8 Cl, Bi 4 NbO 8 Cl, and Bi 2 NbO 5 F have been synthesized by the MSS. − Using the MSS, Li et al successfully synthesized Bi 4 TaO 8 Cl square nanoplates with a regular orthorhombic structure, an edge length of 500 nm, and a thickness of 100 nm (Figure ). Novel Bi 4 NbO 8 Cl nanosheets with 3D architecture and layered lanthanide oxychloride were also synthesized using the MSS method. , …”

“…311 Novel Bi 4 NbO 8 Cl nanosheets with 3D architecture and layered lanthanide oxychloride were also synthesized using the MSS method. 314,315…”

Ba3CrN3H: A New Nitride-Hydride with Trigonal Planar Cr4+

“…We have investigated molten barium and barium/magnesium fluxes for their ability to simultaneously dissolve multiple anions, leading to new compounds such as Ba 2 TeO, Ba 3 Ln 2 O 5 Cl 2 (Ln = Gd to Lu), and Ba 3 Yb 2 O 5 Te. − Since nitrides as well as hydrides are soluble in molten alkaline earth fluxes, we attempted to synthesize novel phases combining anionic nitrogen and hydrogen. In one of our reactions, greenish crystals with hexagonal habit were found, with composition Ba 3 CrN 3 H …”

Synthesis, Crystal Structure, and Optical Properties of Layered Perovskite Scandium Oxychlorides: Sr2ScO3Cl, Sr3Sc2O5Cl2, and Ba3Sc2O5Cl2

“…Common across RP-type layered oxyhalides, halide ions occupy apical sites, which leads to rearrangement of the coordination geometry for the transition metal centers with octahedral symmetry. For example, Sr 2 B ­O 2 Cl 2 ( n = 1; B = Mn, Co, Ni, Cu, Zn) exclusively takes a B O 4 square unit in the basal plane, ,− while Sr 2 B­ O 3 X ( n = 1, B = Mn, Fe, Co, Ni, X = F, Cl), − Sr 3 B 2 ­O 5 Cl 2 ( n = 2, B = Fe, Co), , Ba 3 B 2 ­O 5 Cl 2 ( n = 2, B = Gd–Lu), and Sr 4 B 3 ­O 7.5 Cl 2 ( n = 3, B = Mn, Co) , have B O 5 distorted square pyramids (see Figure ). The high electronegativity of fluoride and the large ionic radius of chloride are important factors causing the reduction in the coordination number of the metal centers.…”