Synthesis and crystal chemistry of microporous titanates K{sub x}(Ti,M){sub 8}O{sub 16} where M=Sc–Ni
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (United States)
- Department of Geology, University of Maryland, College Park, MD 20742 (United States)
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-ray photoelectron spectroscopy. • Cation stoichiometry confirmed by energy dispersive spectroscopy. • Effective moments from magnetization coincide with spectroscopy results.
- OSTI ID:
- 22451110
- Journal Information:
- Journal of Solid State Chemistry, Vol. 220; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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