Modulated Phases and Domain Structure in Double Niobates With Tetragonal Tungsten Bronze - Like Structure

Modulated Phases ◽

Commensurate Phase

ABSTRACTThe domain structure and the commensurate - incommensurate transition of some niobates, with general formula A2BNb5O15 where A = Ba, Sr or Pb and B = Na or K, are examined by using electron microscopy and electron diffraction methods. A model of the commensurate phase at room temperature is proposed and the natureof the incommensurate phase is discussed.

Transmission electron microscopy evidence of a new tetragonal tungsten bronze superstructure

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1997.212.10.708 ◽

1997 ◽

Vol 212 (10) ◽

Cited By ~ 1

Author(s):

F. Krumeich

Keyword(s):

Electron Microscopy ◽

Electron Diffraction ◽

Tungsten Bronze ◽

Transmission Electron ◽

Diffraction Patterns

AbstractElectron diffraction patterns of M

Intergrowth of niobium tungsten oxides of the tetragonal tungsten bronze type

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0107 ◽

2020 ◽

Vol 75 (11) ◽

pp. 913-919

Author(s):

Frank Krumeich

Keyword(s):

Electron Microscopy ◽

Tungsten Bronze ◽

Structural Complexity ◽

Dark Field ◽

Tungsten Oxides ◽

Transmission Electron ◽

Scanning Transmission

AbstractSince the 1970s, high-resolution transmission electron microscopy (HRTEM) is well established as the most appropriate method to explore the structural complexity of niobium tungsten oxides. Today, scanning transmission electron microscopy (STEM) represents an important alternative for performing the structural characterization of such oxides. STEM images recorded with a high-angle annular dark field (HAADF) detector provide not only information about the cation positions but also about the distribution of niobium and tungsten as the intensity is directly correlated to the local scattering potential. The applicability of this method is demonstrated here for the characterization of the real structure of Nb7W10O47.5. This sample contains well-ordered domains of Nb8W9O47 and Nb4W7O31 besides little ordered areas according to HRTEM results. Structural models for Nb4W7O31 and twinning occurring in this phase have been derived from the interpretation of HAADF-STEM images. A remarkable grain boundary between well-ordered domains of Nb4W7O31 and Nb8W9O47 has been found that contains one-dimensionally periodic features. Furthermore, short-range order observed in less ordered areas could be attributed to an intimate intergrowth of small sections of different tetragonal tungsten bronze (TTB) based structures.

Effect of local A-site strain on dipole stability in A6GaNb9O30 (A = Ba, Sr, Ca) tetragonal tungsten bronze relaxor dielectrics

Dalton Transactions ◽

10.1039/c4dt03936j ◽

2015 ◽

Vol 44 (23) ◽

pp. 10738-10745 ◽

Cited By ~ 17

Author(s):

Andrew J. Miller ◽

Andrei Rotaru ◽

Donna C. Arnold ◽

Finlay D. Morrison

Keyword(s):

General Formula ◽

Tungsten Bronze ◽

A Site

A series of isovalently A-site substituted relaxor dielectric tetragonal tungsten bronzes of general formula Ba6−x−ySrxCayGaNb9O30 were investigated.

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

Structures and phase transitions in barium sodium niobate tungsten bronze (BNN)

10.1107/s2052520621010301 ◽

2021 ◽

Vol 77 (6) ◽

Author(s):

Thomas A. Whittle ◽

Christopher J. Howard ◽

Siegbert Schmid

Keyword(s):

Phase Transitions ◽

Room Temperature ◽

Tungsten Bronze ◽

Standard Setting ◽

Experimental Results ◽

Temperature Structure ◽

Sodium Niobate ◽

Space Group ◽

The Subject

The room-temperature structure of the filled tetragonal tungsten bronze, Ba2NaNb5O15 (BNN), has been the subject of a number of studies, and these studies have given an almost corresponding number of different results. From a group theoretical examination of the different possibilities and a review of the published experimental results we conclude that the room-temperature structure is that proposed by Labbé et al. [J. Phys. Condens. Matter (1989), 2, 25–43] in the space group Bbm2 (Ama2 in standard setting) on a 2\sqrt{2}a × \sqrt{2}a × 2c cell. Upon heating, the structure remains ferroelectric but becomes tetragonal (space group P4bm) at 550 K, then paraelectric (space group P4/mbm) at and above 860 K.

Structural studies by electron microscopy: coherent intergrowth of the ReO3and tetragonal tungsten bronze structure types in the system Nb2O5–WO3

Acta Crystallographica Section A ◽

10.1107/s0567739474000040 ◽

1974 ◽

Vol 30 (1) ◽

pp. 29-36 ◽

Cited By ~ 40

Author(s):

S. Iijima ◽

J. G. Allpress

Keyword(s):

Electron Microscopy ◽

Tungsten Bronze ◽

Structural Studies ◽

Tungsten Bronze Structure ◽

Tetragonal Tungsten Bronze

Design of 2D-nanocrystals in water: preparation, structure and functionalization

Pure and Applied Chemistry ◽

10.1515/pac-2017-1105 ◽

2018 ◽

Vol 90 (5) ◽

pp. 833-844

Author(s):

Leonid Aslanov ◽

Valery Zakharov ◽

Ksenia Paseshnichenko ◽

Aleksandr Yatsenko ◽

Andrey Orekhov ◽

...

Keyword(s):

Electron Microscopy ◽

Chemical Composition ◽

High Resolution ◽

Electron Diffraction ◽

Single Crystal ◽

Room Temperature ◽

Energy Dispersive ◽

X Ray ◽

Transmission Electron

AbstractA new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed.

In-situ formation of barium ferrite in iron-doped “tetragonal tungsten bronze”: Elaboration of room temperature multiferroic composites

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2009.02.010 ◽

2009 ◽

Vol 321 (11) ◽

pp. 1773-1777 ◽

Cited By ~ 24

Author(s):

E. Castel ◽

M. Josse ◽

F. Roulland ◽

D. Michau ◽

L. Raison ◽

...

Keyword(s):

Barium Ferrite ◽

Room Temperature ◽

Tungsten Bronze ◽

Iron Doped ◽

In Situ Formation

Structure and electrical properties of tetragonal tungsten bronze Ba2CeFeNb4O15

RSC Advances ◽

10.1039/c5ra16115k ◽

2015 ◽

Vol 5 (94) ◽

pp. 76957-76962 ◽

Cited By ~ 11

Author(s):

Hongqiang Ma ◽

Kun Lin ◽

Laijun Liu ◽

Baoling Yang ◽

Yangchun Rong ◽

...

Keyword(s):

Crystal Structure ◽

Electrical Property ◽

Electrical Properties ◽

Impedance Spectroscopy ◽

Electron Diffraction ◽

Tungsten Bronze ◽

Ac Impedance Spectroscopy ◽

Selected Area Electron Diffraction

X Ray ◽

The crystal structure and electrical property of a tetragonal tungsten bronze ceramic, BaCeFeNb4O15, were investigated by synchrotron X-ray powder diffraction, selected area electron diffraction, and AC impedance spectroscopy.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.215.144 ◽

2014 ◽

Vol 215 ◽

pp. 144-149 ◽

Cited By ~ 8

Author(s):

Sergey M. Zharkov ◽

Roman R. Altunin ◽

Evgeny T. Moiseenko ◽

Galina M. Zeer ◽

Sergey N. Varnakov ◽

...

Keyword(s):

Electron Microscopy ◽

Solid State ◽

Electron Diffraction ◽

Solid State Reaction ◽

Room Temperature ◽

Solid State Reactions ◽

Transmission Electron ◽

Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.