Variable temperature measurements of the complex dielectric permittivity of lossy AlN–SiC composites from 26.5–40 GHz

2001 ◽  
Vol 89 (10) ◽  
pp. 5618-5621 ◽  
Author(s):  
J. P. Calame ◽  
D. K. Abe ◽  
B. Levush ◽  
B. G. Danly
Keyword(s):  
Dielectric Permittivity ◽  
Variable Temperature ◽  
Temperature Measurements ◽  
Complex Dielectric Permittivity ◽  
Sic Composites

Analysis of the complex dielectric permittivity behavior of porous Al2O3–SiC composites in the 1 MHz to 18 GHz frequency range

2007 ◽  
Vol 22 (12) ◽  
pp. 3292-3302 ◽  
Author(s):  
J. Battat ◽  
J.P. Calame
Keyword(s):  
Dielectric Permittivity ◽  
Dielectric Response ◽  
Porous Alumina ◽  
Complex Dielectric Permittivity ◽  
Polymer Precursor ◽  
Frequency Range ◽  
Subsequent Step ◽  
Infusion Method ◽  
Sic Composites ◽  
Scanning Electron

The complex dielectric permittivity of electrically lossy, porous Al2O3–SiC composites was measured as a function of frequency over the range of 0.001 to 18 GHz. These composites were fabricated by an infusion method of incorporating SiC polymer precursor into porous alumina disks. Repeat polymer infusions and pyrolysis steps to 1000 °C were carried out, with some samples undergoing an additional air fire prior to each subsequent step. Generally, it was found that for non-air-fired samples, moderate, controllable losses were attainable over a broad frequency range. By contrast, the dielectric loss attainable for air-fired samples was generally very low. For all samples, various aspects of the variation of permittivity components ϵ′ and ϵ″ with frequency were analyzed, with a view to determine the various factors contributing to dielectric response. Microstructure analysis using scanning electron microscopy was also performed.

Complex dielectric permittivity, electric modulus and electrical conductivity analysis of Au/Si3N4/p-GaAs (MOS) capacitor

2021 ◽  
Author(s):  
Sema Türkay ◽  
Adem Tataroğlu
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Electric Modulus ◽  
Arrhenius Equation ◽  
Rf Magnetron Sputtering ◽  
Oxide Semiconductor ◽  
Complex Dielectric Permittivity ◽  
Mos Capacitor ◽  
Universal Power Law ◽  
Complex Electrical Conductivity

AbstractRF magnetron sputtering was used to grow silicon nitride (Si3N4) thin film on GaAs substrate to form metal–oxide–semiconductor (MOS) capacitor. Complex dielectric permittivity (ε*), complex electric modulus (M*) and complex electrical conductivity (σ*) of the prepared Au/Si3N4/p-GaAs (MOS) capacitor were studied in detail. These parameters were calculated using admittance measurements performed in the range of 150 K-350 K and 50 kHz-1 MHz. It is found that the dielectric constant (ε′) and dielectric loss (ε″) value decrease with increasing frequency. However, as the temperature increases, the ε′ and ε″ increased. Ac conductivity (σac) was increased with increasing both temperature and frequency. The activation energy (Ea) was determined by Arrhenius equation. Besides, the frequency dependence of σac was analyzed by Jonscher’s universal power law (σac = Aωs). Thus, the value of the frequency exponent (s) were determined.

scholarly journals ELECTRODELESS MEASUREMENT TECHNIQUE OF COMPLEX DIELECTRIC PERMITTIVITY OF HIGH-K DIELECTRIC FILMS IN THE MILLIMETER WAVELENGTH RANGE

2016 ◽  
Vol 52 ◽  
pp. 161-167 ◽  
Author(s):  
Igor V. Kotelnikov ◽  
Andrey G. Altynnikov ◽  
Anatoly Konstantinovich Mikhailov ◽  
Valentina V. Medvedeva ◽  
Andrey Kozyrev
Keyword(s):  
Dielectric Permittivity ◽  
Wavelength Range ◽  
Measurement Technique ◽  
Complex Dielectric Permittivity ◽  
Dielectric Films ◽  
Millimeter Wavelength ◽  
High K ◽  
High K Dielectric

scholarly journals OPTICAL PROPERTIES OF LASER-COLOURING MARKED STAINLESS STEEL

2021 ◽  
Vol 3 ◽  
pp. 242-244
Author(s):  
Pavels Narica ◽  
Svetlana Pan’kova ◽  
Vladimir Solovyev ◽  
Alexander Vanin ◽  
Mikhail Yanikov
Keyword(s):  
Stainless Steel ◽  
Optical Properties ◽  
Light Scattering ◽  
Dielectric Permittivity ◽  
Laser Scanning ◽  
Incidence Angle ◽  
Sample Surface ◽  
Laser Scanning Microscopy ◽  
Optical Measurements ◽  
Complex Dielectric Permittivity

Laser colour-marking method often displace conventional marking techniques. Complicated technology of laser-induced periodic surface structure creation on stainless steel samples allows changing their surface morphology and optical properties, which were studied in this work by atomic force microscopy (AFM), laser scanning microscopy, reflectance spectroscopy and ellipsometry. Reflectance spectra of the samples demonstrate reflectance maxima correlate with the visible colours of the samples and with the extrema in the non-monotonic spectral dependences of the derivative of real part of complex dielectric permittivity extracted from the ellipsometric data. Thus, the most intensive light scattering takes place when the real part of complex dielectric permittivity falls down quickly with changing wavelength. We did not observe any “azimuth anisotropy” in our optical measurements at constant incidence angle: the spectra were the same independently of the light incidence plane orientation (parallel or perpendicular to the previous laser light spot scanning direction). We suppose that this selective resonance-like light scattering is due to the sample surface inhomogeneity, which is the result of previous laser treatment. This assumption agrees with estimations based on laser microscope and AFM images as well as with predictions of Mie theory. Thus, the colours of the samples under study are due to the light scattering by randomly distributed surface species with different sizes. 

Double-overdamped-oscillator model of terahertz complex dielectric permittivity of human brain tissues

2021 ◽  
Author(s):  
Guzel R. Musina ◽  
Nikita V. Chernomyrdin ◽  
Irina N. Dolganova ◽  
Vladimir N. Kurlov ◽  
Pavel V. Nikitin ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Human Brain ◽  
Oscillator Model ◽  
Complex Dielectric Permittivity ◽  
Brain Tissues
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