Investigation of the dielectric properties of water adsorbed by zeolites Communication 3. Dielectric losses in the system of NaA zeolite crystals and water at medium degrees of filling

1966 ◽  
Vol 15 (7) ◽  
pp. 1087-1092 ◽  
Author(s):  
V. M. Fedorov ◽  
B. A. Glazun ◽  
M. M. Dubinin ◽  
I. V. Zhilenkov
Keyword(s):  
Dielectric Properties ◽  
Dielectric Losses ◽  
Naa Zeolite ◽  
Zeolite Crystals

Influence of firing profile on microstructural and dielectric properties of LTCC substrates

2017 ◽  
Vol 34 (3) ◽  
pp. 127-130 ◽  
Author(s):  
Alena Pietrikova ◽  
Tibor Rovensky ◽  
Juraj Durisin ◽  
Igor Vehec ◽  
Ondrej Kovac
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dwell Time ◽  
Design Methodology ◽  
Peak Temperature ◽  
Dielectric Losses ◽  
Sintering Process ◽  
Alpha Radiation ◽  
Content Type ◽  
X Ray

Purpose The purpose of this paper is to analyse the influence of various firing profiles on microstructural and dielectric properties of low-temperature, co-fired ceramic (LTCC) substrates in a GHz frequency range. According these analyses, sintering process can be controlled and modified to achieve better performance of devices fabricated from LTCC substrates. Design/methodology/approach Samples from LTCC substrates GreenTape 951 and GreenTape 9K7 were sintered by four firing profiles. Basic firing profile recommended by the manufacturer was modified by increasing the peak temperature or the dwell time at the peak temperature. The influence of firing profile on microstructural properties was analysed according to measurements by X-ray diffractometer (application of the Cu K-alpha radiation and the Bragg-Brentano method), and the influence on dielectric properties (dielectric constant and dielectric losses) was analysed according to measurements by split cylinder resonator method at 9.7 and 12.5 GHz. Findings Rising of the peak temperature or extension of dwell time at this temperature has influence on all analysed properties of LTCC substrates. Size of crystallites can be changed by modification of firing profile as well as microdeformation. In addition, dielectric properties can be changed too by modification of the firing profile. Correlation between microdeformation and dielectric losses was observed. Originality/value The novelty of this work lies in finding the mutual relationship between changes in microstructural (size of grains and microdeformation) and dielectric properties (dielectric constant and dielectric losses) caused by different firing profiles.

Influence of synthesis parameters on NaA zeolite crystals

2013 ◽  
Vol 243 ◽  
pp. 184-193 ◽  
Author(s):  
Xing-dong Liu ◽  
Yi-pin Wang ◽  
Xue-min Cui ◽  
Yan He ◽  
Jin Mao
Keyword(s):  
Naa Zeolite ◽  
Synthesis Parameters ◽  
Zeolite Crystals

scholarly journals Stable dielectric response of low-loss aromatic polythiourea thin films on Pt/SiO2 substrate

2016 ◽  
Vol 06 (01) ◽  
pp. 1650003 ◽  
Author(s):  
A. Eršte ◽  
L. Fulanović ◽  
L. Čoga ◽  
M. Lin ◽  
Y. Thakur ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Response ◽  
High Density Polyethylene ◽  
Dielectric Losses ◽  
Low Loss ◽  
Promising Candidate ◽  
Sio2 Substrate ◽  
Polar Polymer

We have investigated dielectric properties of aromatic polythiourea (ArPTU, a polar polymer containing high dipolar moments with very low defect levels) thin films that were developed on Pt/SiO2 substrate. The detected response is compared to the response of commercially available polymers, such as high density polyethylene (HDPE) and polypropylene (PP), which are at present used in foil capacitors. Stable values of the dielectric constant [Formula: see text] (being twice higher than in HDPE and PP) over broad temperature and frequency ranges and dielectric losses as low as in commercial systems suggest ArPTU as a promising candidate for future use in a variety of applications.

Influence of Gamma-Irradiation on Dielectric Properties of Recycled Polyethylene Composites

2007 ◽  
Vol 1038 ◽  
Author(s):  
Ulmas Gafurov ◽  
Zekie Fazilova
Keyword(s):  
Experimental Data ◽  
Dielectric Properties ◽  
Gamma Irradiation ◽  
High Density Polyethylene ◽  
High Density ◽  
Dielectric Losses ◽  
Γ Irradiation ◽  
Ethylene Propylene ◽  
Recycled Polyethylene ◽  
Polyethylene Composites

AbstractThe influence of γ-irradiation on the dielectric losses (tg δ) and permittivity (ε′) of recycled high density polyethylene (HDPER) thermoplastic dynamic vulcanizates (TDV) has been investigated. The materials and composites that were studied include HDPER:EPDM, HDPER+EPDM+GTR, HDPER+EPDM+GTR/plast; EPDM (ethylene-propylene diamine).The experimental data obtained shows significant differences between dielectric properties different samples, as well as between the unirradiated and γ-irradiated samples.

scholarly journals Recent progress in the shaping and sintering of barium titanate nanoparticles. Application to high permittivity capacitors

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000222-000227
Author(s):  
Sophie Guillemet-Fritsch ◽  
Christophe Voisin ◽  
Roman Nava Quintero ◽  
Pascal Dufour ◽  
Christophe Tenailleau ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Barium Titanate ◽  
Tape Casting ◽  
Casting Process ◽  
Industrial Applications ◽  
The Other ◽  
Precipitation Method ◽  
Dielectric Losses ◽  
High Permittivity ◽  
Co Precipitation

The miniaturisation of electronic components required for many devices involves an increase their volumic efficiency. This work focus on the size reduction of capacitors. They are two ways for increasing the capacity of such passive components. One is to find materials with high permittivity, the other is to reduce the thickness of the films used in multilayers ceramics. Barium titanate, BaTiO3 (BT) nanoparticles were sintered using Spark Plasma Sintering (SPS) because the material presents interesting properties when obtained by SPS [1–3]. In this case, very unusual interesting dielectric properties, a so called “colossal” permittivity value up to several thousands. Moreover, no temperature dependence is observed. However, the values of dielectric losses are too high to consider industrial applications. In order to reduce these dielectric losses, different approaches have been proposed to control the chemistry of grain boundaries. We present here the structural, microstructural and electrical properties of ceramics sintered by SPS from BaTiO3 powders elaborated by co-precipitation method. Different routes tested to improve the dielectric properties of the ceramics are presented and discussed. On the other side, thick films of BT have been prepared. The objective of this work was to develop a BaTiO3 material having an accurate particle size to reduce the thickness of sintered films down to 1 μm. The rheological properties of the slurry have been optimized and, thanks to a suitable tape casting process, homogeneous thin films of 1 μm thickness could be obtained. Some properties of the films are described.

Influence of Phase Composition on Dielectric Properties of Bismuth-Based Ceramics with Scheelite-Type Structure

2014 ◽  
Vol 602-603 ◽  
pp. 683-688
Author(s):  
Dionizy Czekaj ◽  
Agata Lisińska-Czekaj
Keyword(s):  
Phase Composition ◽  
Dielectric Properties ◽  
Solid State ◽  
Pressureless Sintering ◽  
Dielectric Losses ◽  
Frequency Range ◽  
Minor Phase ◽  
Reaction Route ◽  
Excess Amount ◽  
Solid State Reaction Route

Goal of the present research was to study dielectric properties of BiNbO4 ceramics fabricated by solid state reaction route followed with pressureless sintering. The samples were fabricated from the mixture of oxides, viz. Nb2O5 and Bi2O3. Apart from stoichiometric amount an excess of 3%, 5% and 10% by mole of Bi2O3 was used. It was found that an excess amount of Bi2O3 oxide caused formation of Bi5Nb3O15 minor phase in amount of 9wt%, 18wt% and 25wt%, respectively. The dielectric properties were studied by impedance spectroscopy within the frequency range ν=20Hz1MHz and temperature range T=RT550°C. It was found that the presence of the minor phase in amount of 18wt% caused a decrease in dielectric losses of the material under studies.

scholarly journals Dielectric properties of dipolar substances

1944 ◽  
Vol 182 (991) ◽  
pp. 388-403 ◽  
Keyword(s):  
Critical Temperature ◽  
Dielectric Properties ◽  
Local Field ◽  
High Viscosity ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Organic Solids ◽  
Large Group ◽  
Low Viscosity

From an investigation of structure it is shown that there exists a large group of dipolar organic solids whose dipoles have two equilibrium positions with opposite dipole direction. To calculate the dielectric properties Onsager’s theory has been extended and developed into a systematic approximation which converges above a critical temperature. To derive the local field acting on a dipole we have replaced the surroundings by a continuum whose dynamic dielectric properties we have taken into account. As a result we find larger dielectric constants and smaller dielectric losses than in Onsager’s theory. We have also shown that liquids with high viscosity behave similarly to solids, while for liquids with low viscosity there are no such deviations from Onsager’s theory.

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