Tunable Dielectric Properties of BaTiO3/La2O3 Composite Ceramics

2016 ◽  
Vol 848 ◽  
pp. 210-216 ◽  
Author(s):  
Peng Rong Ren ◽  
Qian Wang ◽  
Xin Wang ◽  
Ting Lian ◽  
Gao Yang Zhao
Keyword(s):  
Electron Microscope ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Chemical Method ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Lower Temperature ◽  
Scanning Electron

BaTiO3/La2O3 nanopowders were synthesized by a low-temperature soft chemical method, and then the BaTiO3/La2O3 composite ceramics were prepared. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to characterize the prepared powders and ceramics. And the dielectric properties of the BaTiO3/La2O3 composite ceramics were studied. The results revealed that some of La3+ ions dissolved into the lattice of BaTiO3 at Ba-site and the rest remained at grain boundaries in oxide form of La2O3. With the content of La2O3 increasing, Curie peak of the BaTiO3/La2O3 composite ceramics moved to a lower temperature, and the dielectric loss of the BaTiO3/La2O3 composite ceramics decreased significantly, while the dielectric tunability still kept a relatively high value. The dielectric permittivity and dielectric loss of BaTiO3/La2O3 composite with 10 at.% La2O3 was 227 and 0.0026 at 25 oC and 10 kHz, meanwhile the tunability was up to 17.4% under the electric field of 20 kV/cm.

Solvothermal Synthesis of Bi2Se3 Hexagonal Nanosheet Crystals

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang
Keyword(s):  
Electron Microscope ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.

Synthesis and Study the Properties of a Solar Cell of Gold Nanoparticles Prepared in a Simple Chemical Way

2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
X Ray ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Scanning Electron

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.

Effect of Aging Treatment on Damping Capacity in Mncunife Alloy

2012 ◽  
Vol 246-247 ◽  
pp. 1158-1162
Author(s):  
Xu Fu ◽  
Ning Li ◽  
Yu Hua Wen ◽  
Jing Teng ◽  
Ying Zhang
Keyword(s):  
Electron Microscope ◽  
Aging Treatment ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The Relationship

M2052 alloys with various aging treatments are obtained in order to investigate the relationship between aging treatment and damping capacity by the torsion pendulum, X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results show that M2052 can obtain high damping capacity (δ>0.2) when aged at a range from 400°C to 450°C, and the damping capacity after aged at a lower temperature is higher than that aged at a higher temperature for the maximum values. TEM and XRD results show that fcc-fct transformation occurs after aging treatment. The volumes of fct structures are one of reason to affect the damping capacity in M2052 alloy. The better understanding aging treatment could promote the applications of M2052 alloy.

scholarly journals Influence of Intercalation-Exfoliation-Reduction Technique towards the Physico-Chemical of VPO Catalysts

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Y. C. Wong ◽  
Y. H. Taufiq-Yap
Keyword(s):  
Electron Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vpo Catalysts ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Vpo Catalyst ◽  
Temperature Programmed ◽  
Lower Temperature ◽  
Synthesized Materials

Four VPO catalysts were synthesized through intercalation and exfoliation in various alcohols and subsequent reduction of the exfoliated VOPO4sheets with various alcohols to produce VOHPO4⋅0.5H2O. The resulting VOHPO4⋅0.5H2O that undergoes the intercalation-exfoliation-reduction (IER) process will be further activated into VPO catalysts, and addition of 1 mole % Bi(NO3)3⋅5H2O in the first stage of this experiment has also being investigated. The synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and temperature-programmed reduction (TPR) in H2. Catalytic evaluation of the IER-treated and Bi-doped VPO catalysts was also studied on microreactor. The VPO catalyst produced through IER using 2-butanol and ethanol with addition of Bi, IERC(2Bu-Et)RBi1, gave the highest MA selectivity due to reactive O2−species released from the additional crystalline V5+phase formed by doping 1% bismuth as promoter (O2−-V5+pair) at relative lower temperature. Nevertheless, the VPO catalyst produced through IER using isobutanol, IERC(isoBu), gave the highest activity due to high amount of reactive O−species released from V4+phase (O−-V4+pair) whereby the IERC(isoBu) catalyst synthesized consists of high percentage of V4+(93 %).

Microstructural Characterization of a Fe-Based Compostie Reinforced by TiC

2011 ◽  
Vol 675-677 ◽  
pp. 835-838
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Hong Cheng
Keyword(s):  
Electron Microscope ◽  
Microstructural Characterization ◽  
Interfacial Structure ◽  
Synthesis Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Tic Particle ◽  
Scanning Electron

The present work reported the preparation of TiC/Fe-based composite by the synthesis reaction from Ti, C and Fe. The sintered composites were characterized by X-ray diffraction, scanning electron microscope and transmission electron microscope. TiC, Fe3C and α-Fe were detected by X-ray diffraction analysis. The scanning and transmission electron micrographs revealed the morphology and distribution of the reinforcements, the microstructure of Fe matrix, the interfacial structure of TiC particle-to-Fe matrix. Moreover, the formation reason of the voids in composite was also discussed.

Fabrication of g-C3N4/Y-TiO2 Z-scheme heterojunction photocatalysts for enhanced photocatalytic activity

2021 ◽  
Author(s):  
SongSik Pak ◽  
KwangChol Ri ◽  
Chenmin Xu ◽  
Qiuyi Ji ◽  
Dunyu Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

The g-C3N4/Y-TiO2 Z-scheme heterojunction photocatalysts were successfully synthesized. The powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used for...

STUDY OF HYDROTHERMAL SYNTHESIS AND PROPERTIES OF Bi2Fe4O9

2010 ◽  
Vol 03 (03) ◽  
pp. 173-176 ◽  
Author(s):  
YIBO WANG ◽  
HUAJUN SUN ◽  
JING ZHOU ◽  
BO LI ◽  
CHENGYONG ZHANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Highly oriented Bi2Fe4O9 nanosheets can be fabricated with Fe(NO3)3 ⋅ 9H2O and Bi(NO3)3 ⋅ 5H2O using the low-temperature hydrothermal method. The as-prepared powders are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), which exhibit an excellent orientation along the (00l) planes. The leakage current density and dielectric properties of the nanosheet samples are measured by Radiant Precision Workstation and HP4291B Impedance Analyzer, respectively. The effects of NaOH concentration on the phase transformation, sheet size and morphologies of the Bi2Fe4O9 crystallites are studied in this paper.

Two-Step Fabrication of Nano-PbS on Peacock Feathers Inspired by a Hair-Dyeing Method Used in Ancient Egypt

2013 ◽  
Vol 364 ◽  
pp. 737-741
Author(s):  
Xiao Wei Liu ◽  
Jia Jun Gu ◽  
Fang Yu Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Ancient Egypt ◽  
X Ray Diffraction ◽  
X Ray ◽  
Whole Process ◽  
Transmission Electron ◽  
Dyeing Method ◽  
Scanning Electron

A rapid method towards nanoPbS on peacock feathers was reported and this is inspired by a hair-dyeing technology used in Ancient Egypt thousands of years ago. Original peacock feather was sulfhydrylated by 2, 3-dimercaptosuccinic acid (DMSA) dissolved in alcohol to enhance reaction sites, and then was immersed in the saturated PbO solution in calcium hydroxide and got the PbS peacock feather. The whole process is only two steps and could be completed within two hours. The morphology and structures of the sample were measured by the X-ray diffraction (XRD), Scanning electron microscopy (SEM), and transmission electron microscope (TEM) and results showed that the structure of original peacock feather was well duplicated. Compared with previous works, this method is faster and more efficient and thus has potentials to fabricate other functional sulfides.

scholarly journals Study of structural and dielectric properties of Nickel-doped BaTiO3 material

2019 ◽  
Vol 8 (3) ◽  
pp. 228-233
Author(s):  
Hafes Ed-Dnoub ◽  
Ouafae El Ghadraoui ◽  
Mohammed Zouhairi ◽  
Ahmed Harrach ◽  
Tajeddine Lamcharfi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electron Microscope ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Scanning Electron Microscope ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Perovskite Type ◽  
Scanning Electron

In this work, the effect of nickel (Ni) insertion on the structural and dielectric properties of BaTiO3 material was investigated. A series of powders of composition Ba1-xNixTiO3 (x = 0, 0.05, 0.1, 0.15 and 0.20) were synthesized by solid method. The analysis by X-Ray Diffraction (XRD) shows that the obtained compounds crystallize in a phase of perovskite type. All the peaks are indexed in a phase of quadratic symmetry. Characterization by the Scanning Electron Microscope (SEM) indicates a heterogeneous microstructure of the grains. The study by spectroscopy of impedance in the frequency range [500Hz-1MHz] highlighted the effect of the nickel insertion on the transition temperature and the dielectric constant value.

scholarly journals Microsegregation and Precipitates in Inconel 625 Arc Weld Overlay Coatings on Boiler Pipes / Mikrosegregacja I Wydzielenia W Powłokach Ze Stopu Inconel 625 Napawanych Łukowo Na Rury Kotłowe

2015 ◽  
Vol 60 (4) ◽  
pp. 2599-2606 ◽  
Author(s):  
M. Rozmus-Górnikowska ◽  
M. Blicharski
Keyword(s):  
Electron Microscope ◽  
Inconel 625 ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Weld Overlay ◽  
X Ray ◽  
Transmission Electron ◽  
Overlay Coatings ◽  
Weld Overlays ◽  
Scanning Electron

The aim of this work was to investigate the microsegregation and precipitates formed due to segregation in Inconel 625 arc weld overlay coatings on boiler pipes. Examination of microsegregation and precipitates were carried out by means of a scanning electron microscope (SEM) equipped with an EDS detector as well as a transmission electron microscope (TEM) equipped with a HAADF (STEM) and an EDS detectors. The presence of precipitations in the weld overlay was also confirmed with X-ray diffraction analysis (XRD) of residue in the form of powder that remained after the electrolytic dissolution of weld overlay matrix. The investigations showed that the interdendritic regions were considerably enriched during microsegregation with Nb, and less so with Mo. The distribution of Cr and Fe in the weld overlay is relatively uniform. The value of the partition coefficient k for Mo and Nb is lower than 1. Therefore, these elements segregate during solidification into the liquid and, once solidification is finished, the interdendritic regions are considerably enriched with these elements. The value of k for Cr, Ni and Fe are only slightly higher than 1. Though the Inconel 625 is a solid-solution strengthened alloy, precipitation of secondary phases occurs in weld overlays. Precipitations were identified as a Laves phase and carbonitrides (Nb, Ti)(C, N).

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