Thermodynamics of cationic substitutions on titanyl hydrogen phosphate
作者:V. I. Ivanenko、E. P. Lokshin、S. V. Aksenova、R. I. Korneikov、V. T. Kalinnikov
DOI:10.1134/s0036023608040037
日期:2008.4
Heterophasic substitution of Group I and Group II metal cations for hydrogen ions of titanyl hydrogen phosphate in aqueous solutions has been studied by a potentiometric method. The thermodynamic parameters of the process have been determined. The exchange constants depend on the degree of cation hydration and increase in the following orders: Li+ < Na+ < K+ < Rb+ < Cs+ and Mg2+ < Ca2+ < Sr2+ < Ba2+. Our results make it possible to determine conditions for the efficient deactivation of high-salt liquid radioactive wastes and for the synthesis of stoichiometric compounds of the KTP family.
Synthesis of the fibrous materials ρ-Na0.50H0.50TiOPO4 and ρ-K0.67H0.33TiOPO4 by reaction of ρ-Ti2O(PO4)2(H2O)2 with molten alkali nitrates
作者:Aránzazu Espina、Camino Trobajo、Sergei A Khainakov、José R Garcı́a
DOI:10.1016/s0025-5408(01)00726-7
日期:2001.11
The reaction of rho -TiP with molten MNO3 (M = Na, K) originates the formation of new metal phases, rho -MxH1-xTiOPO4 (x = 0.50, M = Na; x = 0.67, M = K). These compounds maintain the fibrous morphology of their precursors. The processes occur in two differentiated steps with formation of rho -MxH1-xTiOPO4 (x = 0.25, M = Na; x = 0.42, M = K) intermediate phases. An ion-exchange mechanism is proposed for the reaction. Thermal treatment of the novel fibrous alkali metal phosphates produces mixtures of MTiOPO4, MTi2(PO4)(3), and TiO2. (C) 2001 Elsevier Science Ltd. All rights reserved.
NaTiOPO<sub>4</sub>and KTiOPO<sub>4</sub>at 110K
作者:S. Dahaoui、N. K. Hansen、B. Menaert
DOI:10.1107/s0108270197004265
日期:1997.9.15
The title compounds, sodium titanyl phosphate and potassium titanyl phosphate, are isostructural, belonging to a family of compounds with interesting non-linear optical properties. The effect of substitution of K by Na has been analysed by X-ray diffraction at 110 K. The substitution does not modify the geometry of the phosphate groups; however, the Ti-O coordination distances are changed, as well as the relative orientation of the Ti and P polyhedra.
Nagornyi, P. G.; Kapshuk, A. A.; Stus, N. V., Kristallografiya, 1990, vol. 35, p. 370 - 371
作者:Nagornyi, P. G.、Kapshuk, A. A.、Stus, N. V.、Slobodyanik, N. S.