Comparative Study on Crystal Structures and Synthetic Techniques of Ternary Hafnium/Zirconium Fluorides.

Mild hydrothermal synthesis was employed to grow high-quality single crystals of ternary fluoridohafnates at low temperatures. The series of new materials was characterized using single-crystal X-ray diffraction, and the crystal structures of AHfF (A = Mg and Sr), AHfF (A = Ba and Pb), CaHfF, and CdHfF(HO) are discussed herein. Although some material compositions have similar stoichiometries, all of the compositions adopt different structural motifs.

Luminescence and Scintillation of [NbOF]-Dimer-Containing Oxide-Fluorides: Cs(NbOF)F, CsK(NbOF)F, and Cs(NbOF)Cl.

We report three novel Nb-containing oxide-fluorides, Cs(NbOF)F, CsK(NbOF)F, and Cs(NbOF)Cl, which were prepared as high-quality single crystals via a HF-based mild hydrothermal route. The compounds all crystallize in the trigonal crystal system with space group 3̅1. All three compositions form the same framework structure consisting of isolated [NbOF] dimers that create hexagonal channels that are occupied by disordered halide species.

Synthesis of Hydrated Ternary Lanthanide-Containing Chlorides Exhibiting X-ray Scintillation and Luminescence.

A series of new ternary lanthanide-based chlorides, CsEuCl(HO), CsLnCl(HO) (Ln = Gd or Ho), CsTbCl(HO)(HO), CsDyCl(HO), CsErCl(HO), and CsLnCl(HO) (Ln = Y, Lu, or Yb), were prepared as single crystals via a facile solution route. The compounds with compositions of CsLnCl(HO) (Ln = Gd or Ho) and CsLnCl(HO) (Ln = Y, Lu, or Yb) crystallize in a monoclinic crystal system in space groups 2 and 2/, respectively, whereas CsEuCl(HO), CsTbCl(HO)(HO), and CsErCl(HO) crystallize in orthorhombic space groups , , and 222, respectively. CsDyCl(HO) crystallizes with triclinic symmetry in space group 1̅.

BaWOF: a mixed anion X-ray scintillator with excellent photoluminescence quantum efficiency.

A new self-activated X-ray scintillator, BaWO2F4, with an excellent photoluminescence quantum efficiency is reported. Hydrothermally grown single crystals, space group P2/n, exhibit a 3D framework structure containing isolated WO2F4 octahedra. BaWO2F4 exhibits green emission under UV light with a high quantum yield of 53% and scintillates when exposed to X-rays(Cu).

Expansion of the Na M (Ln/An) F Series: Incorporation of Plutonium into a Highly Robust and Stable Framework.

Na MAn F is an extremely versatile framework structure for incorporating tetravalent actinides (An) and cerium along with divalent or trivalent d-metals (M); moreover, the structure exhibits a high resistance to harsh chemical conditions. This extreme robustness can potentially be exploited for the sequestration of plutonium in a stable matrix; however, no Na MPu F compounds have been reported so far. Herein, we present four new plutonium fluorides that have been prepared as single crystals by mild hydrothermal synthesis methods.