Nanocomposite Dielectric Material: Au/SiO2-gel

1992 ◽  
Vol 286 ◽  
Author(s):  
G.C. Vezzoli ◽  
M.F. Chen
Keyword(s):  
Silica Gel ◽  
Microprobe Analysis ◽  
Dielectric Material ◽  
Sol Gel ◽  
Dielectric Strength ◽  
Optimal Topology ◽  
Gold Chloride ◽  
Gel Technique ◽  
High Dielectric ◽  
Nanocomposite Dielectric

ABSTRACTA nanocomposite of clusters of gold atoms in a silica gel matrix has been prepared by the sol-gel technique through reduction of gold chloride. This composite was fabricated to explore novel techniques for materialsengineering new high dielectric strength substances for capacitor applications. The gold islands amidst the silica gel sea are materials-designed to utilize the percolation threshhold phenomenon to create a peak in the dielectricconstant as a function of optimal topology. Experimental results indicate an average dielectric constant of the order of 5000 at 1 kHz, and a maximum versus temperature at ∼ −100°C. Electron microscope and microprobe analysis indicate ellipsoidal Au particles or clusters of a dimension ranging from a hundred angstroms to several thousand angstroms.

scholarly journals High-K dielectric sulfur-selenium alloys

2019 ◽  
Vol 5 (5) ◽  
pp. eaau9785 ◽  
Author(s):  
Sandhya Susarla ◽  
Thierry Tsafack ◽  
Peter Samora Owuor ◽  
Anand B. Puthirath ◽  
Jordan A. Hachtel ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Metal Oxides ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Dielectric Strength ◽  
Dielectric Materials ◽  
High K ◽  
Device Applications ◽  
High K Dielectric ◽  
High Dielectric

Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.

Ferroeleciric Thin Films Intended for Electronic Device Applications

1993 ◽  
Vol 310 ◽  
Author(s):  
A. Patel ◽  
E.A. Logan ◽  
R. Nicklin ◽  
N.B. Hasdell ◽  
R.W. Whatmore ◽  
...  
Keyword(s):  
Thin Films ◽  
Flip Chip ◽  
Electronic Device ◽  
Dielectric Material ◽  
Sol Gel ◽  
Deposition Process ◽  
Dielectric Constants ◽  
Excess Lead ◽  
Starting Solutions ◽  
High Dielectric

AbstractThe need for integrated ferroelectrics as charge storage capacitors has increased dramatically not only for use in radiation hardened and commercial non-volatile memories, but also as possible high dielectric material suitable for capacitor applications. These properties combined with a thin film format, offer the capability of forming very compact capacitor structures suitable for MCM applications through Flip-Chip Bonding, or even integrated directly onto MMIC's. In this paper, the material PbZrxTi1-xO3, where x=l, 0.53, and 0.60 has been assessed. Thin films were produced using a sol-gel technique onto metallised thermally oxidised silicon. The effects on film microstructure and crystallinity with variation in the deposition process will be described. The best films were obtained by incorporating excess lead in the starting solutions, and also by the addition of acetylacetone which was used as a solution modifier. It will be demonstrated that fully perovskite films can be readily obtained at temperatures as low as 450°C. The films were normally 0.3-0.44μm thick with grain sizes of the order of 0.2μm. These films exhibited dielectric constants and loss in the range 170-800 and 1-3% respectively. Measurements upto 3MHz, indicated useful performance with low dispersion. The measured Pr and Ec were in the range 16-22μC/cm2, and 60-120kV/cm respectively.

scholarly journals Enhanced dielectric properties and breakdown strength of polymer/carbon nanotube composites by coating an SrTiO3 layer

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 272-278
Author(s):  
Ruolin Han ◽  
Yuping Liu ◽  
Jinchao Shi ◽  
Guang-Xin Chen ◽  
Qifang Li
Keyword(s):  
Dielectric Properties ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Sol Gel ◽  
Filler Loading ◽  
Filler Concentration ◽  
Dielectric Ceramic ◽  
Nanotube Composites ◽  
Loading Amount ◽  
High Dielectric

Abstract In this work, strontium titanate (STO) was coated on the surface of carbon nanotubes (MWCNTs) through a sol–gel method to form a core–shell structure hybrid powder (STO@MWCNTs). This powder was then added to polydimethylsiloxane to prepare a flexible high-K composite. As coating, STO effectively prevents the overlap and agglomeration of MWCNTs, thereby passivating the percolation threshold of the composite. STO increases the dielectric properties of the composite as a high dielectric ceramic. Under a low filler loading amount of 11 wt%, the dielectric constant and dielectric loss of the composite are 53 and 0.1, respectively. In addition, the composite can still maintain superior breakdown strength and mechanical properties, given the relatively low filler concentration. The enhanced dielectric properties, breakdown strength, and tensile strength make the composite suitable for application as dielectric material in flexible and stretchable energy storage equipment.

scholarly journals Structural, Morphological and Dielectric Studies of Sol Gel Derived Gd Doped SrTiO3-δ

2020 ◽  
Vol 7 ◽  
Keyword(s):  
Sol Gel ◽  
Lattice Parameter ◽  
Dielectric Constants ◽  
Dielectric Studies ◽  
Low Loss ◽  
Gadolinium Doping ◽  
Gel Technique ◽  
Cubic Structure ◽  
Xrd Patterns ◽  
High Dielectric

Gadolinium doped SrTiO3-δ i.e. Sr1-xGdxTiO3-δ for various values of ‘x’ have been successfully synthesized using sol gel technique in the reported work. XRD patterns of the obtained ceramics are found to be sharp and well defined having no impurity phases for all the compositions. Lattice parameter ‘a’ decreases with increase in the amount of Gadolinium. XRD, FESEM and EDX studies confirm the formation of Sr1-xGdxTiO3-δ ceramics with required cubic structure. FESEM/EDX analysis reveals that ceramics possess high density with marginal inter-granular porosity. The dielectric studies show that the synthesized samples possess high dielectric constants, high ac conductivity and low loss factors which further improve with gadolinium doping

scholarly journals AMINO AND MERCAPTO-SILICA HYBRID FOR Cd(II) ADSORPTION IN AQUEOUS SOLUTION

2010 ◽  
Vol 9 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Buhani Buhani ◽  
Narsito Narsito ◽  
Nuryono Nuryono ◽  
Eko Sri Kunarti
Keyword(s):  
Silica Gel ◽  
Sol Gel ◽  
Selectivity Coefficient ◽  
Energy Dispersion Spectroscopy ◽  
X Ray ◽  
Silica Source ◽  
Batch System ◽  
Adsorption Capacities ◽  
Gel Technique ◽  
Silica Hybrid

Modification of silica gel with 3-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane through sol-gel technique producing amino-silica hybrid (HAS) and mercapto-silica hybrid (HMS), respectively, has been carried out using tetraethylorthosilicate (TEOS) as silica source. The adsorbents were characterized using infrared spectroscopy (IR), and X-ray energy dispersion spectroscopy (EDX). Adsorption of Cd(II) individually as well as its binary mixture with Ni(II), Cu(II), and Zn(II) in solution was performed in a batch system. Adsorption capacities of Cd(II) ion on adsorbent of silica gel (SG), HAS, and HMS are 86.7, 256.4 and 319.5 μmol/g with the adsorption energies are 24.60, 22.61 and 23.15 kJ/mol, respectively. Selectivity coefficient (α) of Cd(II) ion toward combination of Cd(II)/Ni(II), Cd(II)/Cu(II), and Cd(II)/Zn(II) ions on HAS adsorbent is relatively smaller than those on HMS adsorbent which has α > 1.   Keywords: adsorption, amino-silica hybrid, mercapto-silica

Incorporation of Polyaniline Into a Silica Gel Via the Sol-Gel Technique

1990 ◽  
Vol 180 ◽  
Author(s):  
F. Nishida ◽  
B. Dunn ◽  
E.T. Knobbe ◽  
P.D. Fuqua ◽  
R.B. Kaner ◽  
...  
Keyword(s):  
Silica Gel ◽  
Conjugated Polymer ◽  
Sol Gel ◽  
Optical Quality ◽  
Emeraldine Base ◽  
Polar Solvents ◽  
Base Form ◽  
Sol Gel Process ◽  
Gel Technique ◽  
Good Optical Quality

ABSTRACTThe sol-gel process has been used to incorporate a conjugated polymer, polyaniline, in silica gel. The emeraldine base form of the polymer is partially solubility in aprotic polar solvents which are compatible with the sol. The effect of sol environment on the emeraldine base form of polyaniline was investigated. The soluble emeraldine base form is maintained at pH ≥ 2.4 enabling good optical quality gels to be synthesized. The type of alkoxysilane and the water ratio used in preparing the sol influence the solubility of the emeraldine base.

DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF LEAD-FREE (Bi0.5Na0.5)0.94Ba0.06TiO3 + x%Ce2O3 + y%La2O3 + z%Y2O3 COMPOUNDS SYNTHESIZED BY SOL–GEL TECHNIQUE

2012 ◽  
Vol 02 (04) ◽  
pp. 1250022
Author(s):  
A. CHAOUCHI ◽  
M. SAIDI ◽  
S. D'ASTORG ◽  
M. RGUITI ◽  
C. COURTOIS
Keyword(s):  
Remanent Polarization ◽  
Piezoelectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Dielectric ◽  
Gel Technique ◽  
Tan Δ ◽  
High Dielectric ◽  
Dielectric And Piezoelectric Properties

( Bi 0.5 Na 0.5)0.94 Ba 0.06 TiO 3 + x% Ce 2 O 3 + y% La 2 O 3 + z% Y 2 O 3 compounds (named BNT–BT– x/y/z) were synthesized by a sol–gel technique, for (x,y,z) = (0,0,0), (0.25, 0.25, 0.25), (0.25, 0.5, 0.5), (0.5, 0.25, 0.25) and (0.5, 0.5, 0.25). The structural variation according to the different system compositions is investigated by X-ray diffraction analyses. The results shows that the addition of Ce2O3 , La2O3 or Y2O3 in BNT–BT system, do not modify the crystalline structure, and a rhombohedral–tetragonal morphotropic phase boundary is maintained for different dopant addition. The BNT–BT–x/y/z-based ceramics sintered at relatively low temperature (1100°C) exhibit a good densification ratio. The optimum dielectric and piezoelectric properties are obtained with the BNT–BT–0.5/0.25/0.25 composition. High dielectric properties at room temperature (εr > 1000) and low dielectric losses (tan δ < 4 × 10-2) are obtained for this composition. This compound exhibits a piezoelectric constant d33 of 95 pC/N, a good polarization behavior is observed with high remanent polarization Pr of 9.21 μC/cm2 and low value coercitive field Ec of 2.66 kV/mm.

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