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The Superstructure of Lead Tetragonal Tungsten Bronze
Journal of Solid State Chemistry, 2002Abstract Electron-optical studies of the superstructure of lead tetragonal tungsten bronze (lead-TTB) are presented. Samples were synthesized for a range of lead compositions and synthesis conditions. For lead-TTB synthesized for very short reaction times, compositional analysis combined with electron diffraction revealed these specimens to also ...
David A Jefferson
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Unified approach for determining tetragonal tungsten bronze crystal structures
Acta Crystallographica Section A Foundations and Advances, 2014 Tetragonal tungsten bronze (TTB) oxides are one of the most important classes of ferroelectrics. Many of these framework structures undergo ferroelastic transformations related to octahedron tilting deformations. Such tilting deformations are closely related to the rigid unit modes (RUMs).
Smirnov, M., Saint-Grégoire, P.
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Ferroelastic-ferroelectric coupling in a crystal with tetragonal tungsten bronze structure
Ferroelectrics, 1978 Abstract The introduction of Pb ions in the phases with the tetragonal tungsten bronze structure creates ferroelastic properties. The replacement of niobium by tantalum in PB2KNb5O15 allows us to modulate the ferroelectric Curie temperature and the spontaneous strain.
Jean Ravez +2 more
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Formation of tetragonal hydrogen tungsten bronze by reactive mechanical alloying
Journal of Solid State Chemistry, 2007 Hydrogen tungsten bronzes have been synthesized by reactive mechanical alloying monoclinic tungsten (VI) oxide under hydrogen atmosphere. Two milling devices with different energy ranges were used. Regardless of the distinct reaction times, a similar phase evolution was observed with both apparatus.
Urretavizcaya, G. +4 more
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Order and Disorder in Niobium Tungsten Oxides of the Tetragonal Tungsten Bronze Type
Acta Crystallographica Section B Structural Science, 1998 Two superstructures of the TTB type (tetragonal tungsten bronze) exist in the system Nb2O5/WO3. They are caused by an ordered arrangement of pentagonal tunnels filled with metal–oxygen strings. Besides the well known 4:9 phase (Nb8W9O47), which has a tripled b axis, evidence for a new orthorhombic structure, Nb6W8O39 (a = b = 27.3 Å), has been found ...
F. Krumeich
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Active and passive defects in tetragonal tungsten bronze relaxor ferroelectrics
Journal of Physics: Condensed Matter, 2022Abstract Tetragonal tungsten bronze (TTB) based oxides constitute a large family of dielectric materials which are known to exhibit complex distortions producing incommensurately modulated superstructures as well as significant local deviations from their average symmetry.
Bi-Xia Wang +5 more
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On the structural complexity of tetragonal tungsten bronze type niobium tungsten oxides
Zeitschrift für anorganische und allgemeine Chemie, 2021AbstractIn this comparative study, two samples with a slightly different oxygen : metal ratio have been characterized by various electron microscopy methods and by single‐crystal and powder X‐ray diffraction (XRD). A reasonably good fit to the experimental powder XRD patterns could be achieved by Rietveld refinement for both samples Nb8W9O47 and ...
Michael Wörle, Frank Krumeich
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New high permittivity tetragonal tungsten bronze dielectrics Ba2LaMNb4O15: M=Mn, Fe
Journal of Solid State Chemistry, 2010 The new phases Ba2LaMNb4O15: M=Mn, Fe were prepared by solid state reaction at 1100 °C. They have the tetragonal tungsten bronze structure, space group P4/mbm, at room temperature.
Emma E Mccabe, Anthony R West
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Journal of Alloys and Compounds, 2021 International audienceZn-doped tungsten bronze compounds derived from Ba5CaTi2Nb8O30, with Ba5CaTi2-xZnxNb8O30 composition (x=0; 0.04 and 0.08) were synthesized by the conventional solid-state reaction route.
Amine Bendahhou +2 more
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Journal of Magnetism and Magnetic Materials, 2009 Recent studies of ceramics of formula Ba2LnFeNb4O15 (Ln=rare earth) with the “tetragonal tungsten bronze” (TTB) structure have correlated their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases.
M Josse, Dominique Michau
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