Synthesis of Dumbbell-Shaped Triblock Structures Containing Ferroelectric Polymers and Oligoanilines with High Dielectric Constants

2008 ◽  
Vol 41 (17) ◽  
pp. 6265-6268 ◽  
Author(s):  
Siwei Liang ◽  
Jason Claude ◽  
Kui Xu ◽  
Qing Wang
Keyword(s):  
Dielectric Constants ◽  
Ferroelectric Polymers ◽  
High Dielectric

Ferroelectric Polymers with Chemically Tunable Dielectric Constants

2006 ◽  
Vol 949 ◽  
Author(s):  
Yingying Lu ◽  
Jason Claude ◽  
Kun Li ◽  
Qiming Zhang ◽  
Qing Wang
Keyword(s):  
Vinylidene Fluoride ◽  
Structural Characteristics ◽  
Hydrogenation Reaction ◽  
Dielectric Constants ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Thermal Transitions ◽  
Ferroelectric Polymers ◽  
Poly Vinylidene Fluoride ◽  
High Dielectric

ABSTRACTWe present a modular approach toward poly(vinylidene fluoride) based ferroelectric polymers with high dielectric constants and energy densities. This strategy is based on a two-step reaction including the co-polymerization of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) and a subsequent hydrogenation reaction. Due to the similar reactivity of VDF and CTFE in free radical polymerization and quantitative yield of dechlorination reaction, the chemical compositions of the resulting terpolymers can be precisely controlled, leading to tunable Curie temperatures and dielectric constants. A library of the ferroelectric polymers with dielectric constants varying from 11 to 50 measured at 1 kHz and room temperature has been prepared. The structural characteristics including microstructure, chain conformation, and crystallinity of the polymers have been carefully elucidated as a function of the chemical composition by 1H and 19F NMR, Fourier transform infrared spectroscopy, and wide angle X-ray diffraction. The influence of the polymer compositions on thermal transitions and dielectric constants has also been investigated.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

LIMITING CONDUCTANCE OF LYONIUM AND LYATE IONS

1959 ◽  
Vol 37 (1) ◽  
pp. 173-177 ◽  
Author(s):  
Martin Kilpatrick
Keyword(s):  
Mixed Solvents ◽  
Direct Determination ◽  
Solvent Mixture ◽  
Dielectric Constants ◽  
Proton Mobility ◽  
Anhydrous Hydrogen Fluoride ◽  
Ice Leads ◽  
Hydrogen Bonded Systems ◽  
High Dielectric ◽  
Strong Acids

The problem of proton mobility has been considered in H2O–CH3OH, H2O–D2O, and H2O–H2O2 solvents from the current viewpoint of the mechanism of proton mobility for aqueous solutions. Mixed solvents are more complicated in that one must consider the relative basicity and acidity of the species competing for the protons. It is concluded that for dilute solutions of HClO4, where water is replaced by hydrogen peroxide, the decrease in equivalent conductance relative to that of KCl in the same solvent mixture is due to the partial elimination of the proton transfer process.For highly acidic non-aqueous solvents of high dielectric constants such as HF, HCN, and HCOOH, the problem of the weakness of the usual "strong" acids of aqueous solution makes a direct determination of the limiting equivalent conductances difficult. In the case of anhydrous hydrogen fluoride the available experimental evidence indicates that the limiting conductance of the lyonium ion is approximately the same as that of the potassium ion but the lyate ion has a higher limiting conductance than other stable anions.The higher proton mobility in ice leads one to expect that hydrogen-bonded systems may be found where the conductivity may approach that of electronic semiconductors.

A Modular Approach to Ferroelectric Polymers with Chemically Tunable Curie Temperatures and Dielectric Constants

2006 ◽  
Vol 128 (25) ◽  
pp. 8120-8121 ◽  
Author(s):  
Yingying Lu ◽  
Jason Claude ◽  
Bret Neese ◽  
Qiming Zhang ◽  
Qing Wang
Keyword(s):  
Dielectric Constants ◽  
Modular Approach ◽  
Ferroelectric Polymers ◽  
Curie Temperatures

New Perovskite Nanomaterials and Their Integrations into High-k Dielectrics

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000072-000077
Author(s):  
Minoru Osada ◽  
Takayoshi Sasaki
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Bottom Electrode ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Layered Perovskite ◽  
Layer By Layer ◽  
High K ◽  
High K Dielectric ◽  
High Dielectric

We report on a bottom-up manufacturing for high-k dielectric films using a novel nanomaterial, namely, a perovskite nanosheet (LaNb2O7) derived from a layered perovskite by exfoliation. Solution-based layer-by-layer assembly of perovskite nanosheets is effective for room-temperature fabrication of high-k nanocapacitors, which are directly assembled on a SrRuO3 bottom electrode with an atomically sharp interface. These nanocapacitors exhibit high dielectric constants (k &gt; 50) for thickness down to 5 nm while eliminating problems resulting from the size effect. We also investigate dielectric properties of perovskite nanosheets with different compositions (LaNb2O7, La0.95Eu0.05Nb2O7, and Eu0.56Ta2O7) in order to study the influence of A- and B-site modifications on dielectric properties.

A Reusable 3D Printed Cavity Resonator for Liquid Sample Characterization

2018 ◽  
Vol 2018 (1) ◽  
pp. 000389-000392
Author(s):  
Saranraj Karuppuswami ◽  
Saikat Mondal ◽  
Mohd Ifwat Mohd Ghazali ◽  
Premjeet Chahal
Keyword(s):  
Dielectric Constant ◽  
Cavity Resonator ◽  
Dielectric Constants ◽  
Sample Holder ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
Sample Characterization ◽  
3D Printed ◽  
Standard Values ◽  
High Dielectric

Abstract In this paper, additive manufacturing (3D printing) is used to fabricate and demonstrate a reusable microfluidic coupled rectangular cavity resonator for characterizing liquids in small volumes. The designed cavity operates in the fundamental TE101 mode and resonates at 4.12 GHz. The resonance of the cavity is perturbed by the sample placed in a small volume sample holder through a slot in the top cover. Two different perturbation configurations are investigated: i) strongly coupled (liquids with low to medium dielectric constants), and ii) weakly coupled (liquids with medium to high dielectric constant). The sample holder is loaded with different solvents and the shift in the resonance frequency is monitored. Based on these changes, the dielectric constant of the solvent is theoretically estimated and compared to standard values. The reusable liquid sensor holds significant potential in identifying and quantifying unknown liquid samples in the supply chain.

Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

2008 ◽  
Vol 368-372 ◽  
pp. 1817-1819
Author(s):  
Cui Hua Zhao ◽  
Bo Ping Zhang ◽  
Yong Liu ◽  
Song Jie Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Co Doping ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Coating Method ◽  
High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

Effect of MWCNT carboxyl functionalization on the shear rheological and electrical properties of HMS-PP/MWCNT foams

2020 ◽  
pp. 0021955X2094309
Author(s):  
Olavo S Bianchin ◽  
Guilherme HF Melo ◽  
Rosario ES Bretas
Keyword(s):  
Impedance Spectroscopy ◽  
Rheological Properties ◽  
Polarized Light ◽  
Multiwall Carbon Nanotubes ◽  
Dynamic Mechanical Properties ◽  
Dielectric Constants ◽  
Scanning Calorimetry ◽  
Cellular Density ◽  
Foaming Behavior ◽  
High Dielectric

Different concentrations of multiwall carbon nanotubes (MWCNT) and carboxyl functionalized MWCNT (MWCNT-COOH) were added to a high melt strength polypropylene (HMS-PP) to produce foams with high dielectric constants, using azodicarbonamide (AZO) as blowing agent. The AZO foaming behavior and the crystallization, thermal properties, steady state and oscillatory shear rheological properties of the nanocomposites were analyzed by polarized light optical microscopy (PLOM), differential scanning calorimetry (DSC), thermogravimetry analyses (TGA) and parallel plate rheometry. The morphology, the dielectric and dynamic mechanical properties (DMTA) of the foams were also studied by scanning electron microscopy (SEM), impedance spectroscopy and bending method, respectively. A decrease in crystallite size and an increase in the HMS-PP overall crystallinity promoted by the presence of both types of MWCNTs was observed, as well as an increase in the crystallization temperatures. From these results and from the analyses of the rheological properties, it was possible to predict that the 5 wt.% MWCNT foam would have the lowest bubble growth rate, the 1.5 wt.% MWCNT-COOH the highest, while the 3 wt.% MWCNT-COOH composition would have the slowest bubble stability (and consequently the highest cellular density) and the 1.5 wt.% MWCNT-COOH the fastest. Also, it was possible to predict that only the 5 wt.% MWCNT-COOH foam would have a percolated and electrically conductive structure. All these predictions were confirmed by the resultant morphology and impedance spectroscopy results. The highest mechanical damping was displayed by the 3 wt.% MWCNT-COOH foam, while the lowest by the 5 wt.% MWCNT-COOH foam. Regarding the dielectric properties, the 1.5 wt% MWCNT-COOH foam was found to be the most suitable to be used as a capacitor material; this foam was also the less dense of all the samples.

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