Results 151 to 160 of about 712 (189)

Incommensurate phases in ferroelectric tetragonal tungsten bronzes

Ferroelectrics, 1981
Abstract Using X-ray scattering, incommensurate phases have been disclosed in some well known ferroelectric tetragonal tungsten bronzes. The results are compared to those recently obtained for Barium Sodium Niobate. It is shown that the existence of incommensurate phases is probably a basic feature for this structural family, which is provoked by a ...
J. Schneck, J. C. Toledano, R. Whatmore, F. W. Ainger   +3 more
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Phenomenological analysis of tetragonal tungsten bronze ferroelectrics

Journal of Materials Science, 1992
A simple Devonshire form has been derived for the phenomenological elastic Gibbs function to describe the elasto-dielectric parameters of simple proper ferroelectrics in the tungsten bronze structure family which has 4/mmm prototypic point symmetry. For the assumption that all temperature dependence is carried by the Curie-Weiss behaviour implicit in ...
L. E. Cross, R. R. Neurgaonkar
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Preparation and properties of tetragonal tungsten oxyfluoride bronzes

Journal of Solid State Chemistry, 1973
Reaction of tungsten(VI) oxide and tungsten metal in the presence of dilute solutions of hydrofluoric acid under hydrothermal conditions has resulted in the formation of a series of tetragonal oxyfluoride bronzes having the composition WO3−χFχ (0.03 ⩽ x ⩽ 0.09). These compounds are isostructural with the tetragonal bronze Na0.10WO3.
T.G. Reynolds, A. Wold
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Dielectric ceramics with relaxors and a tetragonal tungsten bronze

Journal of the European Ceramic Society, 1992
Abstract Type II ferroelectric ceramics with high dielectric constants and flat curves e = f(T) have, until now, only been obtained with oxides which exhibit the perovskite structure. Another family of oxides, the tetragonal tungsten bronze (TTB)-type niobates, should be of great interest for such applications because of their structure, which is ...
J.M. Haussonne, G. Desgardin, A. Herve, B. Boufrou   +3 more
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On the structure of tetragonal tin-tungsten bronzes

Materials Research Bulletin, 1972
Abstract The structures of two bronzes of composition Sn0.11WO3 and Sn0.25WO3 have been investigated by single-crystal methods. They are the well-known tetragonal structures with 5-sided and 4-sided tunnels passing through a matrix of linked W-O octahedra.
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Acoustic phonons in unfilled tetragonal tungsten-bronze crystals

Phase Transitions, 2018
We have studied several unfilled tetragonal tungsten-bronze crystals (SBN-35, CBN-28, CBN-30, CBN-32) by differential scanning calorimetry, Brillouin spectroscopy and piezoresponse-force microscopy...
E. Buixaderas, P. Bérešová, P. Ondrejkovič, P. Vaněk, M. Savinov, P. Bednyakov, J. Dec, D. Mareš, M. Ševčík, M. Landa   +9 more
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Ferroelectric properties of tetragonal tungsten bronze single crystals

Ferroelectrics, 1984
Ferroelectric tetragonal tungsten bronze (T.B.) family single crystals, e.g., SBN, BSKNN, KLN, SKN and PBN, have been grown and their ferroelectric properties have been investigated. The results show that the dielectric, piezoelectric, and electromechanical coupling coefficients are significantly large for these crystals; however, they are markedly ...
R. R. Neurgaonkar, J. R. Oliver, L. E. Cross   +2 more
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Formation of nanocrystalline tetragonal oxide tungsten bronzes on platinum

Russian Metallurgy (Metally), 2017
Cyclic voltammetry is used to study the formation of tetragonal oxide tungsten bronze of the composition K x Na y WO3 on a Pt(110) substrate during electrodeposition from a K2WO4–Na2WO4–WO3 melt. The potential ranges in which cathode products of various compositions and morphologies form are found. K x Na(0.66–x)WO3 crystals are shown to form according
A. V. Kosov, O. L. Semerikova, S. V. Vakarin, A. A. Pankratov, S. V. Plaksin, Yu. P. Zaykov   +5 more
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Electronic structure of tetragonal tungsten bronzes and electrochromic oxides

Applied Physics, 1977
X-ray photoemission spectra of the band structures of WO3, crystalline HxWO3 and the tetragonal and cubic bronzes MxWO3 (M=Li, Na) exhibit great similarity. In the bronzes tungsten 5d conduction band states are occupied. The tungsten 4f core level spectra of these materials have an unusual, but characteristic structure attributed to a combination of ...
G. K. Wertheim, M. Campagna, J. -N. Chazalviel, D. N. E. Buchanan, H. R. Shanks   +4 more
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Quaternary Lead–Niobium–Tungsten Oxides Based on the Tetragonal Tungsten Bronze Structure

Journal of Solid State Chemistry, 2001
Abstract High-resolution electron microscopy and diffraction studies of fully oxidized and reduced Pb–Nb–W–O oxides are presented. The phases observed were superstructures of tetragonal tungsten bronze (TTB), formed by ordering of pentagonal columns (PCs) and pentagonal tunnels (PTs).
Sarah K. Haydon, David A. Jefferson
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