Preparation and Characterization of Forsterite and Measurement of its Dielectric Constant and Loss Factor in the Frequency Range of 100 Kc/S to 25 Mc/S

1979 ◽  
Vol 38 (3) ◽  
pp. 89-95 ◽  
Author(s):  
P. K. Ghosh ◽  
A. R. Das
Author(s):  
A. Ege Engin ◽  
Abdemanaf Tambawala ◽  
Madhavan Swaminathan ◽  
Swapan Bhattacharya ◽  
Pranabes Pramanik ◽  
...  

2010 ◽  
Vol 97-101 ◽  
pp. 1091-1096
Author(s):  
Dong Fang Han ◽  
Qun Tang ◽  
Qing Meng Zhang ◽  
Lei Wang ◽  
Ju Du

The structure and property of Ce-doped Ba0.2Sr0.8TiO3 (BST) were investigated as a function of Ce content. The density experiment results confirmed that increasing the Ce doping ratio caused the decrease in shrinkage factor of BST in the sintering procedure. Additionally, both Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis showed that the grain size of Ce-doped BST was dependent on the Ce content. Further more, the dielectric constant and dielectric loss had a curve relationship with increasing Ce content. The improvement of the electrical properties of Ce doping BST may be related to the decrease in the concentration of oxygen vacancies. According to the research, the diameter of grain, the dielectric constant and loss factor of the 1mol% Ce-doped Ba0.2Sr0.8TiO3 were 500nm, 365.8 and 0.0063, respectively.


2012 ◽  
Vol 02 (04) ◽  
pp. 1250020 ◽  
Author(s):  
P. THOMAS ◽  
K. B. R. VARMA

The glasses in the system (100 - x) TeO2 –x CaCu3Ti4O12 , (x = 0.25 mol. % to 3 mol.%) were fabricated. The color varied from olive green to brown as the CaCu3Ti4O12 (CCTO) content increased in TeO2 matrix. The X-ray powder diffraction and differential scanning calorimetric analyses that were carried out on the as-quenched samples confirmed their amorphous and glassy nature respectively. The dielectric constant and loss in the 100 Hz–1 MHz frequency range were monitored as a function of temperature (50–400°C). The dielectric constant [Formula: see text] and the loss (D) increased as the CCTO content increased in TeO2 at all the frequencies and temperatures under investigation. Further, the [Formula: see text] and D were found to be frequency-independent in the 50–200°C temperature range. The value obtained for the loss at 1 MHz was 0.0019 which was typical of low loss materials, and exhibited near constant loss (NCL) in the 100 Hz–1 MHz frequency range. The electrical relaxation was rationalized using the electric modulus formalism. These glasses may be of considerable interest as substrates for high frequency circuit elements in conventional semiconductor industries owing to their high thermal stability.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2908
Author(s):  
Hailong Chen ◽  
Yudong Xu ◽  
Mengqi Liu ◽  
Tao Li

According to specific formulas, the mixing of rubber samples occurs by two methods: open mixing and internal mixing. The effects of frequency, mixing process, carbon black (CB) content, zinc oxide (ZnO) content, and stearic acid (SA) content on the dielectric properties of rubber materials were studied. The results showed that the effects of the mixing process on the dielectric properties of the rubber samples cannot be ignored, and the appropriate mixing process should be selected when preparing the required rubber materials. The dielectric constant and loss factor of the rubber samples vary depending on the frequency. The dielectric constant had a peak and valley value, while the loss factor only had a peak. The dielectric constant and loss factor of rubber samples were significantly affected by the content of CB, ZnO, and SA. The peak frequency decreased with the increase in CB content, however, the dielectric constant increased with an increase in CB content. The higher the ZnO content, the lower the peak frequency. In addition, the dielectric constant and loss factor increased with an increase in ZnO content. The higher the SA content, the greater the peak frequency. In addition, the dielectric constant and loss factor decreased with an increase in SA content. It is hoped that the experimental results obtained can provide guidance for the study of the dielectric properties, microwave absorption properties, and microwave heating characteristics of rubber polymers.


2020 ◽  
Vol 7 (1) ◽  
pp. 110-116
Author(s):  
Lubis Satzen ◽  
Samson D. Yusuf ◽  
Abdulmumini Z. Loko ◽  
Lucas W. Lumbi

Author(s):  
K.Ch. Varada Rajulu ◽  
B.N. Mohanty

This study presents the dielectric and conductivity properties as function of temperature and frequency of wood based composites. These properties were measured by an open-ended coaxial probe at frequency range between 100 kHz to 100MHz, temperature from 30OC to 200OC which is fully computer interfaced. It has been observed that dielectric constant (ε') and dielectric loss factor (ε") increase with increasing temperature and decrease with increasing frequency. At low temperature region, the conductivity depends significantly on the frequency. However, with the increase in temperature dielectric relaxation takes place and the dependency of the conductivity on frequency get reduced. The patterns of variation were established for the studied specimens and discrepancies were discussed. The study of dielectric properties will help in improving the drying, heating and gluing processes of wood and wood based products.


Author(s):  
Nadera Najib ◽  
Kok Yeow You ◽  
Mauricio Perez ◽  
Robin Augustine

A developed six-port reflectometry (SPR) system was integrated to measure the relative permittivity of tumor and normal breast tissue for medical diagnostic purpose. In order to obtain an accurate and precise measurement, the calibration process was done to the SPR using the well-known three-standard technique. Next, the studied dielectric probe was connected to the calibrated measurement-port of the SPR. The open end of the probe aperture was dibbed into the normal and tumor synthetic breast tissue samples to measure the synthetic breast tissues dielectric constant, ɛrʹ, and loss factor, ɛrʺ in the frequency range of 1.5 GHz to 3.3 GHz. Finally, the comparative studies were conducted between commercial VNA with Keysight 85070E dielectric probe and the studied SPR-probe system based on the measured magnitude of the reflection coefficient, phase shift, dielectric constant, and loss factor of the synthetic breast samples. The maximum absolute errors of the measured reflection coefficient magnitude, phase shift, dielectric constant, and loss factor were found to be 0.01, 1.07°, 1.12, and 0.75, respectively. It was ascertained that the predicted dielectric constant, ɛrʹ, is able to differentiate between normal, (ɛrʹ < 50) and tumor, (ɛrʹ > 50) breast tissues.


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