Measurements of complex dielectric permittivity and magnetic permeability of Ba- and Sr- ferrites in the range 1-10 cm-1 (30-300 GHz)

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.

Download Full-text

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

Progress In Electromagnetics Research M ◽

10.2528/pierm16100505 ◽

2016 ◽

Vol 52 ◽

pp. 161-167 ◽

Cited By ~ 1

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

Download Full-text

OPTICAL PROPERTIES OF LASER-COLOURING MARKED STAINLESS STEEL

Environment Technology Resources Proceedings of the International Scientific and Practical Conference ◽

10.17770/etr2021vol3.6516 ◽

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.

Download Full-text