scholarly journals Microstructure and Nonohmic Properties of SnO2-Ta2O5-ZnO System Doped with ZrO2

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Xiuli Fu ◽  
Feng Jiang ◽  
Ruichao Gao ◽  
Zhijian Peng
Keyword(s):  
Detection Limit ◽  
Leakage Current ◽  
Processing Method ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Zno Varistor ◽  
Conventional Ceramic Processing

The microstructure and nonohmic properties of SnO2-Ta2O5-ZnO varistor system doped with different amounts of ZrO2(0–2.0 mol%) were investigated. The proposed samples were sintered at 1400°C for 2 h with conventional ceramic processing method. By X-ray diffraction, SnO2cassiterite phase was found in all the samples, and no extra phases were identified in the detection limit. The doping of ZrO2would degrade the densification of the varistor ceramics but inhibit the growth of SnO2grains. In the designed range, varistors with 1.0 mol% ZrO2presented the maximum nonlinear exponent of 15.9 and lowest leakage current of 110 μA/cm2, but the varistor voltage increased monotonously with the doping amount of ZrO2.

B2O3-Doped ZnO-Pr6O11 Based Varistor Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1277-1280
Author(s):  
Yue Ping Wang ◽  
Zhi Jian Peng ◽  
Hai Feng ◽  
Cheng Biao Wang ◽  
Zhi Qiang Fu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Nonlinear Coefficient ◽  
Processing Method ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Doped Zno ◽  
New Phase ◽  
Conventional Ceramic Processing

B2O3-doped ZnO-Pr6O11 based varistor ceramics were fabricated by sintering samples at 1350 °Cfor 2h with conventional ceramic processing method. The microstructure and electrical properties of the as-prepared samples were investigated. X-ray diffraction analysis showed that after the addition of B2O3 with the amount designed in this study, no new phase was examined in the detection limit. Through scanning electron microscopy it was found that the doping of B2O3 can promote the growth of ZnO grains, and the sintering of the samples. The result of electrical properties indicated that the nonlinear coefficient and varistor voltage of the samples could be improved to some extent with appropriate doping amount of B2O3, resulting in the highest nonlinear coefficient 6.7, lowest leakage current 329 μA/cm2, and highest varistor voltage 92.4 V/mm, respectively.

Microstructure and Electrical Properties of Al2O3-Doped Ba0.9Ca0.1Ti0.8Zr0.2O3 Based Dielectric Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 734-737
Author(s):  
Yue Ping Wang ◽  
Xiao Hui Wang ◽  
Zhi Jian Peng ◽  
Long Tu Li
Keyword(s):  
Electrical Properties ◽  
Processing Method ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Low Dielectric ◽  
Dielectric Ceramics ◽  
New Phase ◽  
Conventional Ceramic Processing

Al2O3-doped Ba0.9Ca0.1Ti0.8Zr0.2O3(short for BCTZ) based dielectric ceramics were fabricated by sintering samples at 1300°C for 2h with conventional ceramic processing method. The microstructure and electrical properties of the as-prepared samples were investigated. X-ray diffraction analysis showed that after the addition of Al2O3with the amount designed in this study, no new phase was examined in the detection limit. Through scanning electron microscopy it was found that the doping of Al2O3can help the growth of BCTZ grains, and the relative permittivities of the samples. The result of electrical properties indicated that the resistance and the break voltage of the samples could be improved to some extent with appropriate doping amount of Al2O3resulting in the highest dielectric constant ~17000, low dielectric loss <10%, and highest break voltage 8.4 kV/mm, respectively.

Microstructure and nonohmic properties of SnO2–Ta2O5–TiO2 varistor system doped with CuO

2014 ◽  
Vol 28 (15) ◽  
pp. 1450085 ◽  
Author(s):  
Zhijian Peng ◽  
Ruichao Gao ◽  
Feng Jiang ◽  
Jianfeng He ◽  
Xiuli Fu
Keyword(s):  
Processing Method ◽  
Minor Amount ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Field Versus ◽  
Xrd Patterns ◽  
A Minor ◽  
Conventional Ceramic Processing

The microstructure and nonohmic properties of SnO 2– Ta 2 O 5– TiO 2- CuO varistor system were investigated. The proposed samples were doped with different contents of CuO (0–6 mol%) and sintered at 1400°C for 2 h with conventional ceramic processing method. In all the samples, the commonly identified phase was SnO 2 (rutile); however, with increasing doping amount of CuO , the peaks of CuO phase emerged in the X-ray diffraction (XRD) patterns. Scanning electron microscopy (SEM) examination on the fractured surfaces of the samples revealed that a minor amount of CuO dopant can facilitate the sintering of the varistor ceramics, but excessive CuO would mainly segregate at grain-boundaries. The doped CuO may also act as a modifier in the SnO 2 based varistors. The measured electric-field versus current-density characteristics of the samples indicated that both nonlinear exponent and varistor voltage increased with increasing doping amount of CuO up to 3 mol% and then decreased with excessive CuO .

Effect of La2O3 substitutions on structure and dielectric properties of Bi2O3–ZnO–Nb2O5-based pyrochlore ceramics

1999 ◽  
Vol 14 (2) ◽  
pp. 546-548 ◽  
Author(s):  
Hong Wang ◽  
Desheng Zhang ◽  
Xiaoli Wang ◽  
Xi Yao
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Crystal Structures ◽  
Structure Change ◽  
Lower Amount ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conventional Ceramic Processing ◽  
Structure Properties

The effect of La2O3 substitutions on structure and dielectric properties of Bi2O3 –ZnO–Nb2O5-based ceramics was investigated. Bi1.5-xLaxZn0.5(Zn0.5Nb1.5)O7 samples were prepared by conventional ceramic processing technology. The crystal structure of the Bi1.5Zn0.5(Zn0.5Nb1.5)O7 sample was characterized as a pure cubic pyrochlore. With a lower amount of La2O3 substitution, the crystal structures were still cubic pyrochlore. Superlattice x-ray diffraction line was identified for some compositions. With the increasing amount of La2O3 substitution, the crystal structure gradually transformed from pure cubic pyrochlore to LaNbO4 phase. The dielectric properties regularly changed with the structure change. The structure-properties relations of the ceramics are discussed.

Composition and Dielectric Properties of Ba2Ti9O20-BaFe12O19 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 238-241
Author(s):  
Wen Bo Zhang ◽  
Hong Tao Yu ◽  
Jing Song Liu ◽  
Lin Hong Cao
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Electronic Devices ◽  
Ceramic Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composite Systems ◽  
Sintering Conditions ◽  
Lc Filter ◽  
Conventional Ceramic Processing

In this paper, the composition and dielectric properties of Ba2Ti9O20-BaFe12O19system ceramics were studied. The ceramics were prepared successfully through the conventional ceramic processing. The x-ray diffraction results showed that all specimens were made of multi-phases, and the sintering temperature on the phase structure of the ceramics did not affected. The effects of sintering conditions and the components on the dielectric properties were investigated in detail. The investigations indicated that the initial Ba2Ti9O20/ BaFe12O19ratio had a great effect on the dielectric of the ceramics. The permittivity increased as the BaFe12O19content increased, whereas the dielectric loss decreased in the composite systems, which could be attributed to the variance in the formation of phases. At last, we suggested that further studies on magnetic properties should be considered for the application in electronic devices like LC filter.

Preparation and Photocatalytic Property of TiO2/NiFe2O4 Composite Photocatalysts

2012 ◽  
Vol 518-523 ◽  
pp. 775-779 ◽  
Author(s):  
Dong Dong Tan ◽  
De Fu Bi ◽  
Peng Hui Shi ◽  
Shi Hong Xu
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Methyl Orange Solution ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Uv Illumination ◽  
Composite Photocatalysts ◽  
Orange Solution

The TiO2/NiFe2O4 (TN) composite nanoparticles with different mass ratios of NiFe2O4 to TiO2 were prepared via sol-gel method. X-ray diffraction was used to characterize the phase structure of TN. The results indicated that adulterating a smidgen of NiFe2O4 into the TiO2 (about 0.1%) can promote the phase transformation of TiO2, however, when the doping amount of NiFe2O4 surpasses 1%, the introduction of NiFe2O4 can inhibit the growth of TiO2 crystal grain and reduce the size of TiO2 crystal grain. The degradation experiment of methyl orange solution under UV illumination (253.7 nm) showed that the content of NiFe2O4 in the TN was higher, the photocatalytic activity of TN was worse, and the 0.1% TiO2/NiFe2O4 calcined at 400 °C presented the best photocatalytic activity.

scholarly journals Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5955
Author(s):  
Qi-Ying Weng ◽  
Ya-Li Zhao ◽  
Jia-Ming Li ◽  
Miao Ouyang
Keyword(s):  
Detection Limit ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Cobalt Atom ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
Chlorobenzoic Acid ◽  
X Ray ◽  
Highly Sensitive ◽  
Hydrogen Bonded

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca− monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca− and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C–H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M−1 and detection limit: 19 μM) and Cr2O72− (Ksv: 12960 M−1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72− in aqueous media.

scholarly journals Electronic Structure of BiFe1−xMnxO3Thin Films Investigated by X-Ray Absorption Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Abduleziz Ablat ◽  
Emin Muhemmed ◽  
Cheng Si ◽  
Jiaou Wang ◽  
Haijie Qian ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectroscopy ◽  
Causal Relation ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Mn Content ◽  
Mn Substitution ◽  
X Ray Absorption

Multiferroic polycrystalline BiFe1-xMnxO3(0≤x≤0.3) thin films have been prepared on the Pt(111)/Ti/SiO2/Si(100) substrates by pulsed laser deposition method. The influence of Mn substitution on the electronic structure and magnetic properties has been studied. X-ray diffraction spectroscopy shows that Mn substitution slightly modulates crystal structure of the BiFe1-xMnxO3system within the same structural phase. According to FeLedge X ray absorption spectroscopy, Fe ions are found to be formally trivalent for doping amountxin BiFe1-xMnxO3. The enhanced magnetization by increasing Mn content is attributed to an alternation degree of hybridization between Fe 3d-O 2pand Mn 3d-O 2porbitals, basing on the carefully examined FeLand OKedge X-ray absorption spectroscopy. The crystal structural and the electronic structural results show a causal relation between them by demonstrating intrinsic mutual dependence between respective variations.

Photoluminescence of Eu3+-Doped La2Mo2O9 Phosphors

2010 ◽  
Vol 663-665 ◽  
pp. 332-335
Author(s):  
En Guo Wang
Keyword(s):  
Sintering Temperature ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
Obvious Effect ◽  
Reaction Method ◽  
X Ray ◽  
Europium Ion ◽  
Scanning Electron

Eu3+-doped La2Mo2O9 phosphor was fabricated by sold-state reaction method. The as-prepared samples were characterized by the application of X-ray diffraction (XRD), scanning electron microscopy (SEM), and emission spectra. The effect of the sintering temperature and doping amount of europium ion on the luminescent properties of La2Mo2O9:Eu3+ was investigated. The results show that the luminescent intensity will reach the strongest when the sintering temperature is equal to 1073 K. The Eu3+ doping amounts also have obvious effect on the luminescent properties.

Study on the Photocatalytic Oxidation of Reactive Brilliant Blue X-BR with Lanthanum-Modified ZnO-TiO2

2014 ◽  
Vol 884-885 ◽  
pp. 237-241
Author(s):  
Lei Zhu ◽  
Yang Fan Xiao ◽  
Xun Wang
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Sol Gel ◽  
Chloride Concentration ◽  
Brilliant Blue ◽  
Semiconductor Materials ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Transmission Electron

The sol-gel method is adopted in this study to prepare the TiO2-composite semiconductor materials doped with ZnO, whose crystal structures are characterized by way of X-ray diffraction and Transmission Electron Microscopy (TEM). It is concluded that the optimal doping amounts of Zn and lanthanum and the calcination temperature are respectively 3%, 0.3% and 500°C. Mixed with water, the photocatalytic oxidation effects of reactive brilliant blue X-BR, taken as the degradation target, was investigated in this study. When the doping amount of lanthanum is 0.3%, the chroma removal rate of the reactive brilliant blue X-BR by lanthanum-modified ZnO-TiO2 can reach 97.3%. The conditions for optimal decolorization rate are: under ultraviolet light for 2h, using the 100mg / L reactive dyes, controlling pH at about 1 and the chloride concentration at 1mol / L.

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