Lyudmila N. Demianets

Mechanism of growth of ZnO single crystals from hydrothermal alkali solutions

AbstractThe results obtained in experiments on the growth of zinc oxide, ZnO, under hydrothermal conditions are generalized. The polar growth and nonstoichiometry of ZnO crystals are analyzed in terms of crystal chemistry with due regard for the physicochemical conditions of the growth medium. The effect of the Li+ and of di-and trivalent metal (Co2+, Fe2+, Mn2+, Fe3+, Mn3+, Sc3+, In3+) impurities on the kinetics and some physical characteristics of ZnO crystals are studied, and the chemical reactions occurring on the surfaces of the (0001) and

Hydrothermal synthesis and crystal structure of ErSeO3Cl

(000\bar 1)

Hydrothermal synthesis and ionic conductivity of CdF2 and low-temperature modifications of PbF2 and PbSnF4

faces are considered.

Room-temperature excitonic lasing in ZnO tetrapod-like crystallites

Single crystals of γ-Li3PO4 have been grown from flux. The 4 × 8 × 9-mm crystals have the cleavage along the [010] and [120] directions. The anisotropy in ionic conductivity in the grown crystals, ((σ ‖ a)/(σ ‖ b) = 2.5 and (σ ‖ a)/(σ ‖ c) = 1.3), is explained by specific features of the γ-Li3PO4 structure.

Substrate orientation and hydrothermal growth of GaPO4 single crystals

Abstract A new erbium–selenium oxychloride, ErSeO3Cl, has been synthesized hydrothermally starting from ErCl3·6H2O and SeO2 in LiCl aqueous solution, and its crystal structure solved from single-crystal X-ray diffraction data. ErSeO3Cl crystallizes in the HoTeO3Cl structure type in the orthorhombic system, space group Pnma (No. 62), with the cell parameters a=7.185(1) A , b=6.890(1) A , c=8.720(2) A , V=431.7(1) A 3 , Z=4. The structure was refined to R1=0.0259, wR2=0.0648 for 35 variables and 508 unique reflections. The 3D structure of ErSeO3Cl is formed from linked ErO5Cl2 polyhedra and SeO3E (E—lone electron pair) polyhedra. We compare the crystal structure of ErSeO3Cl with the structures of other known rare-earth (Bi)–Se(Te) oxyhalides of the common formula MChO3X (M=Ln(Bi), Ch=Se, Te, X=Cl, Br, I).

Hydrothermal synthesis and crystal structure of ErSeO 3Cl

The combinatorial-topological analysis of the structures of framework Li,Ge-germanates of the compositions Li2GeVIGe2IVO6(OH)2 (sp. gr. B2/b), Li2GeVIGe3IVO9 (sp. gr.Pcca), Li4Ge2VIGe7VIO20 (sp. gr. C2), and Li2GeVIGe6IVO15 (sp. gr. Pbcn) has been made with the separation of subpolyhedral structural units (SPSUs) built by octahedra and tetrahedra. The topologically invariant SPSUs are separated in three-dimensional frameworks of the structures. A possible mechanism of the matrix assemblage from the SPSU invariants in crystal structures of the framework Li,Ge-germanates is suggested.

Growth and ionic conductivity of ?-Li 3 PO 4

Single crystals of CdF2 and low-temperature modifications of PbF2 and PbSbF4 are synthesized from high-temperature hydrothermal solutions in the MF2-M′F2-HF (KF, NH4F)-(Pb)-H2O systems, where M = Cd and Pb and M′ = Sn. Ionic conductivity of the synthesized phases showed pronounced anisotropy of fluoride-ion transport. Conductivity of α-PbF2 measured along two directions equals σ∥a = 1.4 × 10−3 Sm/cm and σ∥c = 2.3 × 10−4 Sm/cm.