scholarly journals Preparation and Dielectric Properties of Co Contained Unfilled Tungsten Bronze Ceramics Ba4RCo0.5Nb9.5O30

2021 ◽  
Author(s):  
Xiaoying Guo ◽  
Weifeng Zhang ◽  
Shan Wu ◽  
Chaozhong Sun ◽  
Changzheng Hu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Rare Earth ◽  
Dielectric Properties ◽  
Tungsten Bronze ◽  
Frequency Dispersion ◽  
Rare Earth Ions ◽  
Ionic Radii ◽  
Tetragonal Tungsten Bronze ◽  
Ceramic Samples ◽  
Full Profile

Abstract In this study, Ba4RCo0.5Nb9.5O30 (R = La, Nd, Sm, Eu) (BRCN) ceramics were synthesized using a high-temperature solid-state reaction. The effects of rare-earth ions with different ionic radii at A sites on the phase structure, microstructure, and dielectric properties of ceramics have been systematically studied. The full profile refinement XRD results show that all ceramic samples are tetragonal tungsten bronze (TTB). As the radius of the rare-earth ions decreases, the relaxation ferroelectric phase transition transforms into the dispersed phase transition, and the frequency dispersion of the ceramic samples gradually decreases. The high-frequency shift of Raman peak indicates that lattice distortion is severe. P-E loops under maximum applied electric field showed that BRCN ceramics can be used for energy storage.

Synthesis and dielectric properties of Ba1−xR2x/3Nb2O6 (R: rare earth) with tetragonal tungsten bronze structure

1999 ◽  
Vol 19 (6-7) ◽  
pp. 1071-1075 ◽  
Author(s):  
Naoki Wakiya ◽  
Jui-Kai Wang ◽  
Atsushi Saiki ◽  
Kazuo Shinozaki ◽  
Nobuyasu Mizutani
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Tungsten Bronze ◽  
Tungsten Bronze Structure ◽  
Tetragonal Tungsten Bronze

Crystallization and dielectric properties of SrO–BaO–Nb2O5–GeO2 tungsten–bronze glass–ceramics

2001 ◽  
Vol 16 (7) ◽  
pp. 2057-2063 ◽  
Author(s):  
Jiin-Jyh Shyu ◽  
Hsin-Wei Peng
Keyword(s):  
Heat Treatment ◽  
Dielectric Properties ◽  
Tungsten Bronze ◽  
Glass Ceramics ◽  
Dielectric Behavior ◽  
Dendritic Morphology ◽  
Dielectric Constants ◽  
Two Stage ◽  
Tetragonal Tungsten Bronze ◽  
Stage Heat Treatment

The crystallization and dielectric properties of SrO–BaO–Nb2O5–GeO2 glass–ceramics were investigated. One- and two-stage heat-treatment methods were used to convert the parent glass to glass–ceramics. Strontium barium niobate (SBN) with a tetragonal tungsten-bronze structure formed as the major crystalline phase. When the crystallizing temperature/time was increased, the secondary crystalline BaGe2O5 phase coexisted with SBN. BaGe2O5 formed as a surface layer grown from the surface into the interior of the sample. The dendritic morphology of SBN crystals was examined. The glass–ceramics crystallized by two-stage heat treatment have higher dielectric constants than those crystallized by one-stage heat treatment. The highest dielectric constant that was obtained in the present glass–ceramics was 320. The glass–ceramics showed relaxor-type dielectric behavior.

Effect of rare earth on dielectric properties of Mn contained unfilled tungsten bronze ceramics

2019 ◽  
Vol 30 (18) ◽  
pp. 17393-17404
Author(s):  
Shan Wu ◽  
Chaozhong Sun ◽  
Zhe Guo ◽  
Changzheng Hu ◽  
Laijun Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Tungsten Bronze

scholarly journals A tetragonal tungsten bronze-type photocatalyst: Ferro-paraelectric phase transition and photocatalysis

2016 ◽  
Vol 37 (8) ◽  
pp. 1257-1262 ◽  
Author(s):  
Dayong Fan ◽  
Ruifeng Chong ◽  
Fengtao Fan ◽  
Xiuli Wang ◽  
Can Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Paraelectric Phase ◽  
Tungsten Bronze ◽  
Paraelectric Phase Transition ◽  
Tetragonal Tungsten Bronze

Study of the Influence of Eu3+ Ions in the Bandgap of K2NdNb5O15 Nanopowders

2015 ◽  
Vol 820 ◽  
pp. 378-383
Author(s):  
Eliane Ayumi Namikuchi ◽  
Ana Maria Pires ◽  
Marcos Augusto Lima Nobre ◽  
Silvania Lanfredi
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Tungsten Bronze ◽  
Small Variation ◽  
Rare Earth Ions ◽  
Tetragonal Symmetry ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Tetragonal Tungsten Bronze ◽  
Modified Polyol Method

Ferroelectric semiconductors oxides with tetragonal tungsten bronze TTB-type structure doped with rare earth ions have been investigated in recent years due their promising optical properties. K2Nd(1-x)EuxNb5O15 nanopowders, where x = 0, 0.0025, 0.025, 0.05 and 0.1 were synthesized by the modified polyol method and characterized by X-ray diffraction and diffuse reflectance spectroscopy UV-Vis. Single phase and crystalline powders of tetragonal symmetry with non-centrosymmetric space group P4bm were obtained. The diffuse reflectance spectra were similar to the profile of a semiconductor material with the presence of thin transitions of Eu3+ in europium-doped K2NdNb5O15, as well as the transitions of Nd3+. The method of Kubelka-Munk was used for the estimation of bandgap energy. The values around 3.7 eV showed small variation with the concentration of Eu3+ ions in the K2NdNb5O15 host structure. The transitions were identified as direct ones type.

scholarly journals Dielectric properties of LiF-B2O3 glasses doped with certain rare earth ions

1998 ◽  
Vol 21 (4) ◽  
pp. 341-347 ◽  
Author(s):  
A V Ravi Kumar ◽  
B Apparao ◽  
N Veeraiah
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Rare Earth Ions
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