Impact of Sr on the performance of BaTi0.9Zr0.1O3–BaTiO3 dielectric powders

2014 ◽  
Vol 28 (14) ◽  
pp. 1450114 ◽  
Author(s):  
Jing Wang ◽  
Guijuan Rong ◽  
Tingwei Wang ◽  
Hao Yao
Keyword(s):  
Dielectric Constant ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Liquid Phase Method ◽  
Dielectric Performance ◽  
Composition Inhomogeneity ◽  
Tan Δ ◽  
Constant Maximum

BaTi 0.9 Zr 0.1 O 3– Ba 1-x Sr x TiO 3 fine-powders are synthesized by two-step liquid phase method. Phase analysis and microstructure evaluation conducted by X-ray diffraction and scanning electron microscopy confirm the perovskite structure of the ceramic grain. Different Sr content is considered to optimize the density and dielectric performance. The dielectric constant increases and dielectric loss decreases with the rising of Sr content until x = 0.05. At the doping content of 5%, the dielectric constant maximum of 42,430 and excellent Y5V dielectric material can be obtained due to composition inhomogeneity and compact properties. Its dielectric properties are as follows: ε RT = 36,914, tan δ < 0.09, ΔC/C 20° C at -30° C and 80°C are -58.98% and 14.94%, respectively, and the breakdown strength Eb ≥ 5.2 kV ⋅ mm -1.

Development of High-Dielectric-Strength Ceramic Film Capacitors for Advanced Power Electronics

2012 ◽  
Vol 2012 (1) ◽  
pp. 000609-000616
Author(s):  
Beihai Ma ◽  
Manoj Narayanan ◽  
Shanshan Liu ◽  
Sheng Tong ◽  
U. (Balu) Balachandran
Keyword(s):  
Dielectric Constant ◽  
Power Electronics ◽  
Room Temperature ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
X Ray Diffraction ◽  
Lead Lanthanum Zirconate Titanate ◽  
Solution Deposition ◽  
Ceramic Film ◽  
High Dielectric

Ceramic film capacitors with high dielectric constant and high breakdown strength are promising for use in advanced power electronics, which would offer higher performance, improved reliability, and enhanced volumetric and gravimetric efficiencies. We have grown lead lanthanum zirconate titanate (PLZT) on nickel foils and platinized silicon (PtSi) substrates by chemical solution deposition. A buffer layer of LaNiO3 (LNO) was deposited on the nickel foils prior to the deposition of PLZT. We measured the following electrical properties for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively: remanent polarization, ≈25.4 μC/cm2 and ≈10.1 μC/cm2; coercive electric field, ≈23.8 kV/cm and ≈27.9 kV/cm; dielectric constant at room temperature, ≈1300 and ≈1350; and dielectric loss at room temperature, ≈0.06 and ≈0.05. Weibull analysis determined the mean breakdown strength to be 2.6 MV/cm and 1.5 MV/cm for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively. Residual stress analysis by x-ray diffraction revealed compressive stress of ≈-520 MPa in the ≈2-μm-thick PLZT grown on LNO buffered Ni foil, but a tensile stress of ≈210 MPa in the ≈2-μm-thick PLZT grown on PtSi substrates.

SINTERING BEHAVIOR AND DIELECTRIC PROPERTIES OF Ba0.985Bi0.01TiO3-Ba0.9955La0.003TiO3 FINE-POWDERS

2013 ◽  
Vol 27 (12) ◽  
pp. 1350081 ◽  
Author(s):  
JING WANG ◽  
SHENGLIN JIANG ◽  
CHUNZHENG WANG ◽  
HAO YAO ◽  
TINGWEI WANG
Keyword(s):  
Dielectric Properties ◽  
Temperature Stability ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
Fine Powders ◽  
Microstructure Evaluation ◽  
Maximum Dielectric Constant ◽  
Composition Inhomogeneity ◽  
Tan Δ

Ba 0.985 Bi 0.01 TiO 3- Ba 0.9955 La 0.003 TiO 3 fine-powders were synthesized by two-step soft chemistry method. Phase analysis and microstructure evaluation conducted by X-ray diffraction and scanning electron microscopy confirmed the provskite structure of the ceramic grain. Different sintering temperatures were considered to optimize the density and dielectric properties. The maximum dielectric constant decreased first, and then increased before dropping again, reflecting the change of relative density. Samples sintered at 1270°C exhibited the best temperature stability due to composition inhomogeneity and compact properties. The dielectric properties of the sample sintered at 1270°C were: ε = ~8,960, tan δ < 0.28, ΔC/C20° C at -55°C, 110°C and 150°C were -5.2%, 13.8% and -12.8%, respectively.

TiO2 Supported on Crude Sepiolite by Liquid Phase Method

2010 ◽  
Vol 96 ◽  
pp. 251-256
Author(s):  
Xiao Yan Wang ◽  
Zhi Jiang Ji ◽  
Jing Wang ◽  
Hai Jian Li
Keyword(s):  
Hydroxyl Radical ◽  
Electron Microscope Study ◽  
Phase Method ◽  
Natural Light ◽  
X Ray Diffraction ◽  
Scanning Electron Microscope Study ◽  
X Ray ◽  
Liquid Phase Method ◽  
Spin Resonance ◽  
Scanning Electron

TiO2 was supported on crude sepiolite by boiling reflux method. According to the X-ray diffraction, TiO2 is rutile-anatase mixing type while the composite prepared by the same method is rutile crystal. Scanning electron microscope study shows that TiO2 balls grow onto fibrous sepiolite like strings of grapes. The binding energy of Ti2p becomes 0.2eV lower in the composite. The photocatalytic performances are evaluated through studying the ability of generating hydroxyl radical（•OH）by electron spin resonance(ESR), and the decomposition rate of methyl orange in aqueous solution. It is found that the quantity of hydroxyl radical increases and the photocatalytic activity is enhanced for TiO2/sepiolite composite under natural light.

Epoxy-Based Dielectric Materials for Solid Insulator: Preparation, Dielectric Properties, and Breakdown Performance

2013 ◽  
Vol 798-799 ◽  
pp. 197-200
Author(s):  
Nan Li ◽  
Wei Deng ◽  
Hui Gang Sun
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Epoxy Matrix ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
The Other ◽  
Mixing Ratio ◽  
Solid Insulator ◽  
Polymeric Samples

In this article, epoxy-based dielectric materials for solid insulator were investigated. First, epoxy-based polymeric samples with different permittivities were prepared by incorporating a mixture of two fillers (Al2O3 and SrTiO3) into epoxy matrix. Then, dielectric properties were characterized for the epoxy-based samples by using a dielectric spectrometer with varied frequency. Finally, breakdown tests were performed under AC voltage to characterize the breakdown strength of the dielectric material. Results indicated that the permittivity (dielectric constant) of epoxy-based materials can be adjusted only by changing the mixing ratio of two types of fillers. On the other hand, the obtained dielectric materials showed acceptable breakdown strength with the present amounts of fillers.

Dielectric properties of Ln(Mg1/2Ti1/2)O3 as substrates for high-Tc superconductor thin films

1999 ◽  
Vol 14 (6) ◽  
pp. 2484-2487 ◽  
Author(s):  
Seo-Yong Cho ◽  
Chang-Hun Kim ◽  
Dong-Wan Kim ◽  
Kug Sun Hong ◽  
Jong-Hee Kim
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Room Temperature ◽  
Ybco Thin Film ◽  
X Ray Diffraction ◽  
High Tc ◽  
X Ray ◽  
High Tc Superconductor ◽  
Tan Δ ◽  
Superconductor Thin Films

Ln(Mg1/2Ti1/2)O3 (Ln = Dy, La, Nd, Pr, Sm, Y) compositions have been prepared, and their pertinent properties for use as thin film substrates for YBa2Cu3Ox (YBCO) were measured. X-ray diffraction shows that Ln(Mg1/2Ti1/2)O3 compositions have noncubic symmetry and the GdFeO3-type structure. Dielectric constant measurements revealed values between 22 and 27, which are larger than those of the LnAlO3 family. Quality factor (=1/ tan δ) of the ceramic specimens measured at room temperature was larger than 3000 at 10 GHz. Among the compounds, La(Mg1/2Ti1/2)O3 exhibited the highest dielectric constant and the lowest dielectric loss. Chemical reaction was observed between Ln(Mg1/2Ti1/2)O3 (Ln = Dy, Sm, Y) and YBCO after annealing a 1 : 1 mixture at 950 °C. Considering dielectric and physical properties, La(Mg1/2Ti1/2)O3 and Sm(Mg1/2Ti1/2)O3 were determined to be suitable substrates for YBCO thin film used in microwave applications.

Boosted dielectric performance of organic‐inorganic nanocomposites based on BaTiO3 via 2D TiO2 templates

2021 ◽  
Author(s):  
Se Yeon Park ◽  
Moonjeong Jang ◽  
Wooseok Song ◽  
Sun Sook Lee ◽  
Dae Ho Yoon ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Polymer Materials ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
Dielectric Performance ◽  
Inorganic Nanocomposites ◽  
Ceramic Fillers ◽  
High Dielectric ◽  
Nanocomposite Dielectric

Abstract Organic-inorganic hybrid dielectrics composed of nanoscale ceramic fillers in polymer matrices have attracted considerable attention because they can overcome the inherent limitations such as the low dielectric constant, high dielectric loss, and low film density associated with mechanically flexible pristine polymer materials. Barium titanate (BaTiO3), a representative perovskite-based material with a high permittivity, is suitable for applications as nanofillers in nanocomposite dielectrics. X-ray diffraction combined with Raman analysis suggest that a two-step hydrothermal synthesis, which uses synthesized TiO2 nanosheets as a template, is an effective method for the synthesis of pure BaTiO3 nanoparticles compared with other methods. Ultrasonic treatment is employed to disperse BaTiO3 nanoparticles with different concentrations in polyvinyl alcohol (PVA) polymer, and the dielectric performance of the nanocomposite films has been examined. In this study, 20 wt% BaTiO3-PVA nanocomposite dielectric showed superior capacitance and dielectric constant performance, i.e., five times higher than that of the pristine PVA.

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 723-729 ◽  
Author(s):  
D. NITHYAPRAKASH ◽  
B. PUNITHAVENI ◽  
J. CHANDRASEKARAN
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Ac Conductivity ◽  
Thermal Evaporation ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Cbh Model ◽  
X Ray ◽  
Correlated Barrier Hopping ◽  
Tan Δ

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.

EFFECT OF Ni DOPING ON STRUCTURAL AND DIELECTRIC PROPERTIES OF GdFeO3

2013 ◽  
Vol 22 ◽  
pp. 179-183 ◽  
Author(s):  
PAWANPREET KAUR ◽  
K. K. SHARMA ◽  
RAVI KUMAR ◽  
RABIA PANDIT
Keyword(s):  
Dielectric Constant ◽  
Ac Conductivity ◽  
Tangent Loss ◽  
X Ray Diffraction ◽  
Ni Doping ◽  
Reaction Route ◽  
Lattice Contraction ◽  
X Ray ◽  
Ion Substitution ◽  
Tan Δ

The polycrystalline samples of GdFe 1-x Ni x O 3(x=0.0, 0.1) are prepared by solid state reaction route, their structure is analyzed by powder X-ray diffraction (XRD) and Rietveld refinement. We are also studying the behavior of dielectric constant (ε′), tangent loss (tan δ) as a function of frequency from 75 kHz to 5 MHz and AC conductivity (σac) from 75 kHz to 1 MHz for both the compositions at room temperature. It is noticed that Ni 3+ ion substitution results in lattice contraction and enhancement in dielectric constant, tangent loss and AC conductivity.

scholarly journals Microstructure and Electrical Properties of Fluorene Polyester Based Nanocomposite Dielectrics

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3053
Author(s):  
Wenchao Zhang ◽  
Kuo Zhao ◽  
Feng Guan ◽  
Jinghua Yin ◽  
Yu Feng ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Composite Films ◽  
High Strength ◽  
Sio2 Nanoparticles ◽  
X Ray ◽  
Low Dielectric ◽  
High Dielectric ◽  
Corona Resistance

As a new type of dielectric material, the low dielectric constant and corona resistance life of fluorene polyester (FPE) restricts the range of its applications. In order to simultaneously achieve a high dielectric constant and the long corona aging lifetime of FPE, SiO2 nanoparticles were chosen as additive to prepare FPE-based composite films. The microstructure of the composite film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and small-angle X-ray scattering (SAXS). The dielectric performances of the composites, including the dielectric constant, breakdown strength and corona resistance lifetime, were investigated. The results show that the introduced SiO2 does not destroy the structure of the FPE molecular chain and that it increases the thickness of the filler-matrix interface. The dielectric constant of SiO2/FPE composites increased from 3.54 to 7.30 at 1 Hz. Importantly, the corona resistance lifetime increased by about 12 times compared with the pure FPE matrix. In brief, this work shows what possibilities there might be when considering the potential applications of high-strength insulating materials.

scholarly journals Dielectric Constant Enhancement with Low Dielectric Loss Growth in Graphene Oxide/Mica/Polypropylene Composites

2021 ◽  
Vol 5 (2) ◽  
pp. 52
Author(s):  
Chao-Yu Lee ◽  
Chia-Wei Chang
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Dielectric Loss ◽  
Energy Density ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Dielectric Strength ◽  
Self Healing ◽  
Organic Thin Film ◽  
Low Dielectric

Polypropylene has been widely used as dielectric material in organic thin-film capacitors due to their high breakdown strength, low dielectric loss and self-healing capability. However, polypropylene’s energy density is relatively low. Increasing the energy density of polypropylene by adding materials with a high dielectric constant is commonly used. Still, it often leads to an increase in dielectric loss, lower dielectric strength and other shortcomings. In this study, a thin 2D platelet of mica/graphene oxide composite material was made from exfoliated mica as a substrate and attached by graphene oxide. The mica/graphene oxide platelets were added to polypropylene to make a plastic dielectric composite. The non-conductive flat inorganic additive can increase the dielectric constant and dielectric strength of the composite without increasing dielectric loss. The tiny mica/graphene oxide platelets can significantly improve the dielectric properties of polypropylene. The results show that by adding a small amount (less than 1 wt%) mica/graphene oxide, the relative dielectric constant of polypropylene can increase to more than 3.7 without causing an increase in dielectric loss and the dielectric strength of polypropylene can also enhance.

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