A Study on Nanometer-Sized BaTiO3-Based Dielectric for Ni-MLCC with Y5V Specification

2005 ◽  
Vol 475-479 ◽  
pp. 1129-1132
Author(s):  
Zhen Ji ◽  
Zhigang Xiao ◽  
Sen Wang ◽  
You Song Gu ◽  
Cheng Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dielectric Material ◽  
Dissipation Factor ◽  
Dielectric Medium ◽  
Sintering Behavior ◽  
Manufacturing Cost ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Transmission Electron

In order to meet the demand on the miniaturization and manufacturing cost reduction of the multilayer ceramic capacitors we have developed a nano-BaTiO3-based non-reducible dielectric material through a soft chemical route. The particle size has been decreased down to the level of 30nm and the dielectric medium could be co-fired with Ni-electrodes under a N2+H2 reducing atmosphere. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and volume shrinkage have been employed to detect the sintering behavior and microstructure evolution including grain growth, pore formation and body densification. Dielectric measurements showed, after a sintering process at 1200°C for 2h, the dielectric constant was 8800, the dissipation factor was less than 2%, the insulation resistance was about 12~13exp Ω.cm, and the temperature coefficients of capacitance were less than 22% and -82% at -30°C and 85°C respectively. On the basis of the results it is anticipated that the material could be used for the Ni-MLCC with thin dielectric layers with a Y5V specification in the Electron Industries Association standard.

Effects of Co content in TiO2–Co composite prepared by alloying–recomposition–oxidation–sintering process on its mechanical properties and microstructure

2019 ◽  
Vol 53 (24) ◽  
pp. 3483-3495
Author(s):  
Seungkyun Yim ◽  
Ilsong Park ◽  
Jeshin Park
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Diffraction Field ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Transmission Electron ◽  
Content Range ◽  
Structural Characterizations

TiO2–Co composite powders with various Co contents were prepared by the alloying-recomposition-oxidation-sintering process. For comparison, conventionally mixed TiO2–Co composites with the same compositions were sintered at 1000, 1100, 1200, 1300, and 1400℃. Structural characterizations were performed using X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive spectroscopy, and transmission electron microscopy. All of the sintered samples were more densified. A melted matrix was observed at a temperature higher than 1300℃. The flexural strength and the fracture toughness of the TCA sample were higher than those of the conventionally mixed TiO2–Co sample at the same sintering temperature, while the Vickers hardness exhibited the opposite relationship. The flexural strength and the fracture toughness of the TCA sample increased until a Co content of 14 vol%, followed by decrease at 18 vol%, while those of the conventionally mixed TiO2–Co sample increased in the entire Co content range. The highest flexural strength and fracture toughness were observed for T14CA sintered at 1400℃ (161.3 MPa and 6.39 MPa m−1/2, respectively). Consequently, the desirable Co content in the TiO2–Co composite prepared by the alloying–recomposition–oxidation–sintering process was 14 vol%.

Functionalized Silicate Supported TiO2-ZnO Nanocomposite Film and its Application in Simultaneous Photocatalytic Degradation of Toxic Molecules

2013 ◽  
Vol 764 ◽  
pp. 255-265 ◽  
Author(s):  
R. Dhanalakshmi ◽  
A. Pandikumar ◽  
R. Ramaraj
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Potential Candidate ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Molar Ratios ◽  
Amine Functionalized ◽  
Transmission Electron

The TiO2-ZnO nanocomposite materials ((TiO2-ZnO)NCM) with different molar ratios (Ti:Zn) was synthesized by chemical route and dispersed in functionalized silicate sol-gel matrix (Silicate/(TiO2-ZnO)NCM)). The as prepared Silicate/(TiO2-ZnO)NCM were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The dispersion of the small amount of (TiO2-ZnO)NCM in silicate sol-gel matrix paves the way for the preparation of solid-state thin film photocatalyst which is advantageous for the separation of the catalyst from solution, the substrates and the reaction products. The simultaneous photoinduced oxidation of methylene blue (MB) dye and reduction of Cr (VI) to Cr (III) was examined at different amine functionalized silicate sol-gel embedded (TiO2-ZnO)NCM films. The (TiO2-ZnO)NCM dispersed into the amine functionalized silicate sol-gel matrix (TPDT) exhibited enhanced photocatalytic activity when compared to the (TiO2-ZnO)NCM without the silicate sol-gel. The functionalized silicate sol-gel supported (TiO2-ZnO)NCM is a potential candidate for energy conversion and environment remediation and cleaning applications.

Morphology and Phases of Ni-S Powders Synthesized by Chemical Route

2012 ◽  
Vol 503-504 ◽  
pp. 459-462
Author(s):  
Zhong Quan Ma ◽  
Ke Gao Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
X Ray Diffraction ◽  
Minor Phase ◽  
Chemical Route ◽  
Major Phase ◽  
X Ray ◽  
Powder Product ◽  
Transmission Electron ◽  
Product Powder

The nickel sulfides of NiS and NiS2 have been synthesized successfully at 180 °C and 160 °C by hydrothermal method from NiCl2•6H2O, S powder and NaOH. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the major phase of the powder product obtained at 180 °C is NiS2. The Ni-S powder obtained at 180 °C shows granular and hexagonal shapes with sizes of about 200~300 nm. The product powder obtained at 160 °C has the major phase NiS and minor phase NiS2. The morphology of this product was regular hexagonal flakes with side-length 200nm.

scholarly journals Photoluminescence from SWCNT/Cu Hybrid Nanostructure Synthesized by a Soft Chemical Route

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Rima Paul ◽  
Apurba Krishna Mitra
Keyword(s):  
Electron Microscopy ◽  
Single Wall Carbon Nanotubes ◽  
Visible Range ◽  
Hybrid Nanostructure ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Transmission Electron ◽  
Chemical Technique ◽  
Wet Chemical Technique

We report a simple wet chemical technique to coat single wall carbon nanotubes (SWCNTs) with Cu nanoparticles. The SWCNT/Cu hybrid nanostructure has been characterized using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) study, and Raman spectroscopy. Characteristic optical properties of the nanohybrid structure have been identified through UV-Vis and photoluminescence (PL) spectroscopy. When excited by a radiation of 400 nm wavelength, PL emission in the visible range of 480–620 nm was observed due to charge transfer. This property may be exploited in photovoltaic cells, solar energy conversion, and sensor devices.

Influence of Addition of Polymeric Precursors of Ceramics on Sintering of Al2O3

2012 ◽  
Vol 727-728 ◽  
pp. 1092-1097
Author(s):  
Ana Lúcia Exner Godoy ◽  
José Carlos Bressiani ◽  
Ana Helena de Almeida Bressiani
Keyword(s):  
Electron Microscopy ◽  
Ceramic Composites ◽  
Processing Route ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Sintering Aid ◽  
X Ray ◽  
Polymer Precursors ◽  
Transmission Electron ◽  
Indentation Analysis

The effects of adding polymer precursor on the sintering behavior, microstructure and hardness of alumina ceramics have been studied. Polymer sintering aid polymethylhidrogensiloxane were used for alumina based ceramics sintered at 1650º C. The sintered materials were characterized using: (a) helium picnometry to determine apparent density; (b) x-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy and energy dispersive x-ray spectrometry to determine the microstructure and composition; (c) Vickers indentation analysis to determine the hardness and fracture toughness. The addition of polymethylhidrogensiloxane yielded alumina/mullite composites. The preparation of ceramic composites using small amounts of polymer precursors is suited for alumina based ceramics. The processing route being simple, it has the potential to enable the manufacture of complex shaped pieces.

Synthesis and Optical Properties of CdSe and CdSe/ZnS Core/Shell Quantum Dots

2015 ◽  
Vol 1085 ◽  
pp. 176-181
Author(s):  
Puspendu Barik ◽  
Arup Ratan Mandal ◽  
Denis V. Kuznetsov ◽  
Anna Yu. Godymchuk
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Shell Material ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
The Core ◽  
Transmission Electron

In this work, we have synthesized homogeneous, ordered CdSe and CdSe/ZnS core/shell quantum dots (QDs) by chemical route and characterized them using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Photoluminescence (PL) spectroscopy. Coating with shell material was confirmed by red shift as well as enhancement in the PL peak compared to bare QDs. DLS data showed QDs and core/shell to be stable. PL spectra are red shifted relative to the excitation wavelength. Bare QDs and the core/shell material shows a Stoke-shift of 16 and 18 meV respectively.

DIELECTRIC AND MAGNETIC PROPERTIES OF BaTiO3+MgCuZnFe2O4 NANOCOMPOSITES

2010 ◽  
Vol 24 (03) ◽  
pp. 369-378 ◽  
Author(s):  
K. SADHANA ◽  
K. PRAVEENA ◽  
S. R. MURTHY
Keyword(s):  
Electron Microscopy ◽  
Microwave Sintering ◽  
Dissipation Factor ◽  
Initial Permeability ◽  
Frequency Variation ◽  
X Ray Diffraction ◽  
Weight Percentage ◽  
Microwave Hydrothermal ◽  
Transmission Electron ◽  
Quality Factor Q

Nanocrystalline MgCuZnFe 2 O 4 and BaTiO 3 powders were synthesized using the microwave hydrothermal (M-H) method at 160°C for 45 min for the preparation of x BaTiO 3+(1-x) MgCuZnFe 2 O 4. The nanopowders were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The particle size of the powders was found to be ~30 and ~40 nm for MgCuZnFe 2 O 4 and BaTiO 3, respectively. The nanopowders were mixed at different weight percentages and densified at 910°C for 30 min using the microwave sintering method. The sintered composites were characterized using XRD and scanning electron microscopy (SEM). The density of the composites varies 93–96% of theoretical density. The density of the present composites increases as the weight percentage of BaTiO 3 content increases. The frequency variation of dielectric constant (ε), dissipation factor (D), initial permeability (μi) and quality factor (Q) were measured from 1 kHz to 1 MHz.

scholarly journals The effect of sintering temperatures of TiO2(B)-nanotubes on its microstructure

2018 ◽  
Vol 50 (3) ◽  
pp. 291-298
Author(s):  
H. Sutrisno ◽  
E.D. Siswani ◽  
K.S. Budiasih
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Tio2 Nanotubes ◽  
Single Phase ◽  
Anatase Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Patterns

Titanium dioxide (TiO2)-nanotubes were prepared by a simple technique reflux. The morphologies and microstructures of nanotubes were characterized by high resolution scanning electron microscopy (HRSEM), high resolution transmission electron microscopy (TEM), powder X-ray diffraction (XRD,) energy dispersive X-ray spectroscopy (EDS) and surface area analyzer. The microstructures of TiO2 phases obtained from the sintering process of TiO2-nanotubes for 1 hour at various temperatures from 100 to 1000?C at intervals of 50?C were investigated from the XRD diffractograms. The analyses of morphologies and microstructures from HRSEM and HRTEM images describe the sample as nanotubes. The nanotube is single phase exhibiting TiO2(B) structure. The XRD patterns show that TiO2(B)-nanotubes transform into anatase phase and then become rutile due to increasing sintering temperatures.

Influence of Addition of Polysiloxane on Sintering of Al2O3

2014 ◽  
Vol 798-799 ◽  
pp. 696-702
Author(s):  
Ana Lucia Exner Godoy ◽  
José Carlos Bressiani ◽  
Ana Helena de Almeida Bressiani
Keyword(s):  
Electron Microscopy ◽  
Ceramic Composites ◽  
Nitrogen Atmosphere ◽  
Processing Route ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polymer Precursors ◽  
Transmission Electron ◽  
Cold Pressed

The effects of adding polysiloxane (polymethylsilsesquioxane) on the sintering behavior, microstructure and hardness of alumina ceramics have been studied. The sintering kinetics of cold-pressed specimens was studied by dilatometry. Polymer sintering aid was used for alumina based ceramics sintered at 1650o C. The sintered materials were characterized using helium picnometry, x-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectrometry and Vickers indentation. The addition of polymethylsilsesquioxane yielded alumina/Si2Al4O4N4 composites. The sintering studies in nitrogen atmosphere (1650 °C/1h) revealed that the highest densities were obtained for specimens with 1wt% PMS. The materials prepared with ceramic polymer precursors had higher hardness than the standard specimen. The preparation of ceramic composites using small amounts of polymer precursors is suited for alumina based ceramics. The processing route being simple, it has the potential to enable the manufacture of complex shaped pieces.

Synthesis and characterization of nanocrystalline LaMnO3 modified BaTiO3 ferroelectric ceramics prepared by chemical route

2016 ◽  
Vol 30 (05) ◽  
pp. 1650043 ◽  
Author(s):  
Prasanta Dhak ◽  
Mrinal Kanti Adak ◽  
Debasis Dhak
Keyword(s):  
Electron Microscopy ◽  
Grain Morphology ◽  
Dielectric Constants ◽  
Ferroelectric Ceramics ◽  
Tangent Loss ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Transmission Electron ◽  
Crystallite Sizes

Nanocrystalline Ba[Formula: see text]Ti[Formula: see text]La[Formula: see text]Mn[Formula: see text]O3, [[Formula: see text] = 0.006, 0.008, 0.01 and 0.05] (abbreviated hereafter as BTLM) by chemical route. The phase formation and purity were checked by X-ray diffraction (XRD) study and transmission electron microscopy (TEM). The grain morphology after sintering was studied by scanning electron microscopy (SEM). The crystallite sizes range from 21 nm to 30 nm, while the particle size ranges between 27 nm and 38 nm. The grain size 212 nm and grain density 96.8% were found to be maximum for BTLM [Formula: see text] = 0.05 and [Formula: see text] = 0.01, respectively. The temperature dependence of dielectric constants was found to be more diffused and the peak value of the dielectric constant was decreased and more flat with the increase of the substituent concentration. The tangent loss was found to be decreased and reached to the minimum value of 0.032 for BTLM [Formula: see text] = 0.05. The remnant polarization [Formula: see text], was 10 [Formula: see text]C/cm2 for BTLM [Formula: see text] = 0.01.

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