Dielectric constant tensor of piezoelectric gadolinium calcium oxoborate crystal, GdCa4O(BO3)3, estimated from the electric impedance spectrum

2006 ◽  
Vol 203 (5) ◽  
pp. 979-986 ◽  
Author(s):  
C. Pawlaczyk ◽  
E. Markiewicz ◽  
A. Kłos ◽  
A. Pajączkowska
Keyword(s):  
Dielectric Constant ◽  
Impedance Spectrum ◽  
Electric Impedance ◽  
Constant Tensor

Corrosion Behavior of Five Commonly-Used Steels in Oily and Alcoholic Sewage from Gas Field

2013 ◽  
Vol 815 ◽  
pp. 55-60
Author(s):  
Yun Ma ◽  
Qian Wang ◽  
Xin Min Wu
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Chromium Content ◽  
Impedance Spectrum ◽  
Electric Impedance ◽  
Gas Field ◽  
316L Steel ◽  
Corrosion Pits ◽  
Ferrous Carbonate ◽  
Scanning Electron

The corrosion behavior of commonly-used steels in the oil-containing and alcoholic sewage from gas field was studied combined with polarization curves, electric impedance spectrum (EIS), dynamic corrosion weight loss test, scanning electron microscope (SEM) and energy spectrum (ES) of corrosion products. It was shown that corrosion rate increased with the sequence of 316L, 16Mn, 20#, L360 and 20R steels, and 316L steel was corroded more slightly than 16Mn, 20#, L360 and 20R steels. There were some spot corrosion pits on the surface of L360 and 20R steels. A higher Chromium content of 316L steel led to a stronger corrosion resistance. Ferrous carbonate was the mainly corrosion product on the surface of the four steels. While the corrosion product on the surface of L360 and 20R steels was poor adhered and easy to fall off, and formed some corrosion pits on the steels surface.

Two Equivalent Reduction Methods of Dielectric Constant Tensor for Hexagonal Crystal System Materials

2020 ◽  
Vol 837 ◽  
pp. 146-152
Author(s):  
Chuan Xin Li
Keyword(s):  
Dielectric Constant ◽  
Coordinate System ◽  
Modern Society ◽  
Hexagonal Crystal ◽  
Solid State Physics ◽  
Rectangular Coordinate System ◽  
Crystal System ◽  
Constant Tensor ◽  
Reduction Methods ◽  
Equivalent Reduction

Hexagonal crystal system materials have very important applications in modern society. Dielectric constant tensor of hexagonal crystal system materials is simplified only by the formula in a hexagonal coordinate system, not by the formula often seen in current Chinese solid state physics textbooks. Meanwhile, the equivalence of hexagonal coordinate system and rectangular coordinate system is presented in the paper.

Influence of DC Bias on the Properties of the Piezoelectric Material

2016 ◽  
Vol 852 ◽  
pp. 164-170
Author(s):  
Kang Le ◽  
Yu Jun Feng
Keyword(s):  
Dielectric Constant ◽  
Elastic Constant ◽  
Piezoelectric Material ◽  
Bias Voltage ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Resonance Method ◽  
Impedance Spectrum ◽  
Impedance Analyzer ◽  
Dc Bias

According to the resonant characteristics of piezoelectric materials, in order to get the parameters of piezoelectric materials under DC bias voltage by calculate the impedance spectrum of piezoelectric materials, and the changes of the parameters of piezoelectric materials under DC bias were discussed. This paper measured the impedance spectrum of piezoelectric materials under different DC bias voltage with TH2828S Impedance Analyzer, and found that DC bias voltage made the material impedance spectrum drifted. Various parameters of materials were calculated by the resonance method, it was found that the parameters of piezoelectric materials under varied bias voltage were different, and the behaviours of each parameters under DC bias voltage were obtained.It was consider that the elastic constant and dielectric constant were changed due to the inverse piezoelectric effect of the piezoelectric materials which were under DC bias voltage,so that other parameters were changed.Then the resonant frequent formula of piezoelectric materials under DC bias voltage was deduced.

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