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Title: Synthesis and crystal chemistry of microporous titanates K{sub x}(Ti,M){sub 8}O{sub 16} where M=Sc–Ni

Through salt-flux methods, single crystals of eight novel hollandite-type titanates have been grown with the stoichiometry K{sub x}(Ti{sub 8−y}M{sub y}){sub 8}O{sub 16} for x=y≈1.5 where M{sup 3+}=Sc, Ti, V, Cr, Mn, and Fe, and for x/2=y≈0.75 where M{sup 2+}=Co and Ni. Single crystal and powder X-ray diffraction reveals phase pure crystals with tetragonal space group I4/m. These titanates are microporous oxides with 1-dimensional channels where the non-framework cation, K, resides. In addition to diffraction, spectroscopic methods were used to characterize the chemical composition of both the bulk and surface. X-ray photoelectron spectroscopy affords the oxidation states of the substituted transition metals M on the surface and energy dispersive X-ray spectroscopy the metal ratios, including that of potassium, for an overall accurate description of the chemical composition of both the bulk and surface. Magnetization versus temperature measurements indicate that all phases are Curie paramagnets with effective magnetic moments consistent with the d-electron count given by combined X-ray diffraction and elemental analysis techniques. - Highlights: • Single crystal growth of K{sub x}(Ti,M){sub 8}O{sub 16} for M=Sc–Ni via molten salt flux. • Single crystal and powder X-ray diffraction utilized for structure of all compounds. • Oxidation states for all metals determined by X-raymore » photoelectron spectroscopy. • Cation stoichiometry confirmed by energy dispersive spectroscopy. • Effective moments from magnetization coincide with spectroscopy results.« less
Authors:
; ; ; ;  [1] ;  [2] ;  [1]
  1. Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (United States)
  2. Department of Geology, University of Maryland, College Park, MD 20742 (United States)
Publication Date:
OSTI Identifier:
22451110
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 220; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATIONS; CHEMICAL COMPOSITION; ELECTRONS; HOLLANDITE; MAGNETIC MOMENTS; MAGNETIZATION; MOLTEN SALTS; MONOCRYSTALS; POTASSIUM; POWDERS; SPACE GROUPS; SURFACES; SYNTHESIS; TEMPERATURE MEASUREMENT; TETRAGONAL LATTICES; TITANATES; TRANSITION ELEMENTS; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY; X-RAY SPECTROSCOPY