Study of Ac Conductivity and Dielectric Properties of PMMA with Fe2O3+ Al2O3 Composite Films

2013 ◽  
Vol 209 ◽  
pp. 14-17
Author(s):  
Basavaraja Sannakki ◽  
Anita Gandhe ◽  
V.H. Doddamani
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Polymer Composite ◽  
Composite Films ◽  
Weight Percent ◽  
X Ray ◽  
Morphological Studies ◽  
Tan Δ ◽  
Al2o3 Films

Abstract. The PMMA with Fe2O3+ Al2O3 films at different weight percent have been used for measurement of dielectric properties such as dielectric constant, dielectric loss and a. c. conductivity as a function of frequency over the range 50 Hz – 5 MHz at room temperature. The dielectric constant and the dielectric loss (tan δ) of the polymer composite films decreases exponentially at lower frequencies over the range 100 Hz-1 kHz, where as above 1 kHz the values of dielectric constant remains same. But, it has been observed that the value of dielectric constant of PMMA composite films with Fe2O3+ Al2O3 increases as weight percent of Fe2O3+ Al2O3 increases. The a c conductivity of the polymer composite films remains constant over the frequency range 50 Hz to 300 K Hz and afterwards it increases exponentially. Further, PMMA with Fe2O3+ Al2O3 have been characterized using X-Ray diffractometer for the crystallinity. The morphological studies have been made using the FESEM.

scholarly journals Crystallization and Dielectric Properties of MWCNT /Poly(1-Butene) Composite Films by a Solution Casting Method

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 755
Author(s):  
Lingfei Li ◽  
Qiu Sun ◽  
Xiangqun Chen ◽  
Yongjun Xu ◽  
Zhaohua Jiang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Breakdown Strength ◽  
Composite Films ◽  
Conductive Filler ◽  
Interfacial Polarization ◽  
Solution Casting ◽  
Casting Method ◽  
Solution Casting Method

In this work, poly(1-butene) (PB-1) composite films with multi-walled carbon nanotubes (MWCNT) were prepared by a solution casting method. The relationship between the dielectric properties and the crystal transformation process of the films was investigated. It was indicated that there were two crystal forms of I and II of PB-1 during the solution crystallization process. With the prolongation of the phase transition time, form II was converted into form I. The addition of the conductive filler (MWCNT) accelerated the rate of phase transformation and changed the nucleation mode of PB-1. The presence of crystal form I in the system increased the breakdown strength and the dielectric constant of the films and reduced the dielectric loss, with better stability. In addition, the dielectric constant and the dielectric loss of the MWCNT/PB-1 composite films increased with the addition of MWCNT, due to the interfacial polarization between MWCNT and PB-1 matrix. When the mass fraction of the MWCNT was 1.0%, the composite film had a dielectric constant of 43.9 at 25 °C and 103 Hz, which was 20 times that of the original film.

scholarly journals Effect of TeO2 addition on the dielectric properties of CaCu3Ti4O12 ceramics derived from the oxalate precursor route

2013 ◽  
Vol 03 (04) ◽  
pp. 1350028 ◽  
Author(s):  
P. Thomas ◽  
K. B. R. Varma
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Oxalate Precursor ◽  
X Ray ◽  
Practical Applications ◽  
Low Dielectric ◽  
Precursor Route ◽  
Tan Δ

CaCu 3 Ti 4 O 12 (CCTO) ceramics which has perovskite structure gained considerable attention due to its giant permittivity. But it has high tan δ (0.1 at 1 kHz) at room temperature, which needs to be minimized to the level of practical applications. Hence, TeO 2 which is a good glass former has been deliberately added to CCTO nanoceramic (derived from the oxalate precursor route) to explore the possibility of reducing the dielectric loss while maintaining the high permittivity. The structural, morphological and dielectric properties of the pure CCTO and TeO 2 added ceramics were studied using X-ray diffraction, Scanning Electron Microscope along with Energy Dispersive X-ray Analysis (EDX), spectroscopy and Impedance analyzer. For the 2.0 wt.% TeO 2 added ceramics, there is a remarkable difference in the microstructural features as compared to that of pure CCTO ceramics. This sample exhibited permittivity values as high as 7387 at 10 KHz and low dielectric loss value of 0.037 at 10 kHz, which can be exploited for the high frequency capacitors application.

Perovskite Relaxor Ferroelectric Thick Films Directly Grown from Oxide Precursors by a Low Temperature Hydrothermal Process

2007 ◽  
Vol 334-335 ◽  
pp. 1049-1052
Author(s):  
Hui Qing Fan ◽  
Xiu Li Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Thick Films ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
X Ray ◽  
Morphological Studies ◽  
Phase Characterization

Relaxor-based lead-lanthanum-zirconate-titanate (PLZT) thick films were prepared on Ti substrates by a simplified hydrothermal method, in which the precursors were heated to 150 oC with durations from 8 to 32h. The mixture of oxides was used as the staring materials. The smooth PLZT films with a single perovskite structure were obtained through the synthesis route. Structural and morphological studies were carried out on hydrothermally synthesized films. The influences of the mineralizer concentration on the structural, morphological, and physical characteristics of the particles are studied. Phase characterization and crystal orientation of the PLZT thick films were investigated by x-ray diffraction analysis (XRD). The dielectric constant and dielectric loss of the PLZT thick films were measured. In the frequency range from 1000 to 100 MHz, the dielectric constant and the dielectric loss were very steady.

Dielectric Properties of Li-Doped CaCu3Ti4O12 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 251-256 ◽  
Author(s):  
Ying He ◽  
Huai Wu Zhang ◽  
Yuan Xun Li ◽  
Wei Wei Ling ◽  
Yun Yan Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Secondary Phase ◽  
Doping Amount ◽  
Spectroscopy Analysis ◽  
Low Dielectric ◽  
Tan Δ ◽  
High Dielectric ◽  
Impedance Spectroscopy Analysis

CaCu3Ti4O12 ceramics doped with 0-2.0 wt% Li2CO3 were prepared by the solid-state reaction, and their electric and dielectric properties were investigated. It is found that these ceramics had the properties of high dielectric constant and comparatively low dielectric loss. At the doping amount of 0.5 wt%, the dielectric constant is kept to be 105 with weak frequency dependence below 105 Hz, and its loss tangent (tan δ) is suppressed below 0.1 between 300 Hz-5 kHz (with the minimum value of 0.06 at 1 kHz from 218 K to 338 K). The impedance spectroscopy analysis confirms that the decrease of dielectric loss is mainly due to the increase of resistance in the grain boundary, which may be related to the influence of Ti4O7 secondary phase. Our result indicates that doping Li2CO3 is an efficient method to optimize the dielectric properties of CaCu3Ti4O12.

α/β Phase Transformation in Porous Reaction-Bonded Silicon Nitride Ceramics

2011 ◽  
Vol 194-196 ◽  
pp. 2225-2228
Author(s):  
Jie Xu ◽  
Jun Bo Wang ◽  
Wei Hua Cui ◽  
Xiao Lei Su ◽  
Wan Cheng Zhou
Keyword(s):  
Dielectric Constant ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
Silicon Nitride ◽  
Dielectric Loss ◽  
Point Defects ◽  
Nitriding Temperature ◽  
Β Phase ◽  
Nitride Ceramics ◽  
Tan Δ

Porous reaction-bonded silicon nitride ceramics with different values of α/β ratio were obtained by setting the nitriding temperature and time. The influence of α/β phase transformation on the dielectric properties of porous silicon nitride ceramics has been investigated. The results show that the α/β transformation occurs when the nitriding temperature is higher than 1400°C . The values of α/β ratio decrease with increase of nitriding temperature and time. The dielectric constant ε′ and the dielectric loss tan δ of the samples increase because of the α/β transformation, and the change of the dielectric loss is more obvious. The increase of concentrations of point defects due to the α/β transformation leads to the significant increase of the dielectric loss.

Sintering, Microstructure and Dielectric Properties of Ca-Al-B-Si-O Glass/Al2O3 Composites with Various SiO2 Content

2011 ◽  
Vol 130-134 ◽  
pp. 1516-1519
Author(s):  
Ming Liu ◽  
Hong Qing Zhou ◽  
Hai Kui Zhu ◽  
Min Liu ◽  
Jian Xin Zhao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Silicon Dioxide ◽  
Bulk Density ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Tan Δ ◽  
Silicon Dioxide Content

The effects of silicon dioxide addition on the sintering, microstructure and microwave dielectric properties of Ca-Al-B-Si-O glass/Al2O3 composites were investigated. Results show that: Increasing the silicon dioxide content in the glass leads to the corresponding rise of bulk density, dielectric constant of the LTCC materials and the decrease of its dielectric loss and porosity. A bulk density of 2.92 g·cm-3, a porosity of 0.2%, aεr value of 7.11 and a tan δ value of 0.00096(measured at 10 MHz) are obtained for 68 wt% silicon dioxide of the samples sintered at 875°C for 30 min.

DIELECTRIC PROPERTIES OF Li-Sb FERRITES

2005 ◽  
Vol 19 (18) ◽  
pp. 899-905 ◽  
Author(s):  
SHIVAJI CHONGTHAM ◽  
SUMITRA PHANJOUBAM ◽  
H. N. K. SARMA ◽  
RADHAPIYARI LAISHRAM ◽  
CHANDRA PRAKASH
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Room Temperature ◽  
Substitution Level ◽  
Higher Temperature ◽  
Tan Δ ◽  
Almost All ◽  
Frequency Curves

Dielectric properties such as dielectric constant (ε′) and dielectric loss tangent ( tan δ) of Li 0.5+x Fe 2.5-2x Sb x O 4 ferrites, 0.10≤ x ≤0.30 in steps of 0.05 have been investigated as a function of composition, frequency and temperature. The dielectric constant showed dispersion with frequency in the range of 100 Hz–1 MHz. Peaks were observed in the tan δ versus frequency curves for almost all the samples. The temperature variation of dielectric constant for the different samples was studied at 10 kHz in the temperature range from room temperature to 433 K. Peaks were observed for some of the samples. The peaks were seen to shift towards higher temperature region as the substitution level increases. The mechanisms involved in the processes are discussed in this paper.

Dielectric Properties of PVDF-TrFE/PMMA: TiO2 Multilayer Dielectric Thin Films

2012 ◽  
Vol 576 ◽  
pp. 582-585 ◽  
Author(s):  
Ismail Lyly Nyl ◽  
Mohamad Hafiz Mohd Wahid ◽  
Zulkefle Habibah ◽  
Sukreen Hana Herman ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Spin Coating ◽  
Frequency Range ◽  
Dielectric Thin Films ◽  
Two Samples ◽  
Coating Method ◽  
Tan Δ ◽  
Multilayer Dielectric

This paper reports on the dielectric properties of multilayer PVDF-TrFE/PMMA:TiO2 thin film. Two samples were fabricated on ITO substrates; one with PVDF-TrFE only and another PMMA:TiO2 on PVDF-TrFE on (PVDF-TrFE/PMMA:TiO2). Both samples were produced by spin coating method. Dielectric properties were characterized using impedance spectroscopic. Dielectric constant, k, capacitance and dielectric loss, tan δ values of PMMA:TiO2/PVDF-TrFE were measured in the frequency range 0 – 50 kHz. The result for dielectric loss did not show any significant different between the samples with and without nanocomposite PVDF-TrFE layer. However, the dielectric constant are affected when depositing a nanocomposite PVDF-TrFE layer on PMMA:TiO2. The dielectric constant is decreased by 0.3 from 7.9 to 7.6.

Sn-doped BaO–TiO2–ZnO Microwave Ceramics

2002 ◽  
Vol 17 (6) ◽  
pp. 1550-1552 ◽  
Author(s):  
Wu Shunhua ◽  
Wang Guoqing ◽  
Zhao Yushuang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Volume Resistivity ◽  
Ceramic Materials ◽  
Microwave Ceramics ◽  
Microwave Ceramic ◽  
Tan Δ

Sn-doped BaO–TiO2–ZnO (BTZ) microwave ceramic materials were investigated as a function of SnO2 content. Addition of a small amount of SnO2 (0.01–0.06 wt%) lowered the sintering temperature of the system to 1160 °C and also greatly reduced the dielectric loss (tan δ), which is closely related to the insulation resistivity. The Sn-doped BTZ materials were found to have excellent dielectric properties at 1 GHz with dielectric constant Ε ≈tangent tan δ ≤ 1 × 10−4, temperature coefficient of dielectric constant, αΕ = 0 ± 30 ppm/°C, and volume resistivity ρv ≥ 1013 ω cm.

scholarly journals Studying the Effect of Titania Additions on some properties of Porcelain

2018 ◽  
Vol 28 (2) ◽  
pp. 169
Author(s):  
Abbas K. Saadon
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Titanium Oxide ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manufacturing Method

The paper presents the production of porcelain for the ceramic by inexpensive natural raw materi-als, the principal raw materials of porcelain composition was selected consisting of 50% kaolin, 25% feldspar, 25% silica, the sample synthesized were characterize by X-ray diffraction (XRD) technique, than study the effect additives at different concentration form titanium oxide (𝑇𝑖𝑂2 )at (2, 5, 10, 15, 20) wt% on some physical and dielectric properties of porcelain. The samples are prepared by the conventional manufacturing method. The physical and dielectric properties of porcelain show that change considerably with the sub-stituent sample. It was found that the increase of the titanium oxide (𝑇𝑖𝑂2 ) additives of all our sample produce increasing in dielectric constant and bulk density, while decreasing with open porosity and dielectric loss tangent.

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