Temperature dependence of the dielectric constant of relaxor ferroelectrics

1998 ◽  
Vol 57 (14) ◽  
pp. 8166-8177 ◽  
Author(s):  
Z.-Y. Cheng ◽  
R. S. Katiyar ◽  
X. Yao ◽  
A. S. Bhalla
Keyword(s):  
Dielectric Constant ◽  
Temperature Dependence ◽  
Relaxor Ferroelectrics

Investigation of Polarization Mechanism of Relaxor Ferroelectrics

1996 ◽  
Vol 453 ◽  
Author(s):  
Z. -Y. Cheng ◽  
R. S. Katiyar ◽  
Yao Xi
Keyword(s):  
Dielectric Constant ◽  
Low Temperature ◽  
Temperature Dependence ◽  
High Precision ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Polar Regions ◽  
Thermally Activated ◽  
Polarization Mechanism ◽  
Constant Maximum

AbstractAddition to thermally activated flips of polar regions in relaxor ferroelectrics, a new polarization mechanism, which originates from the vibrations (breathing) of surface of polar regions, is introduced to explain the dielectric behavior of relaxor ferroelectrics. This new mechanism plays an important role in the dielectric behavior of such materials at low temperature. Based on the above assumption and general dielectric theory, a formula is given to characterize the temperature dependence of the dielectric constant. The correctness of the formula is verified by using it to fit the experimental results of the two typical relaxors. The fitted results show that the method is of high precision and that the temperature of the dielectric constant maximum is decided by the two polarization behavior. It also indicates that the new polarization is a resonance polarization.

Parametric Models of Ultrasonic Piezoelectric Transducers over a Wide Temperature Range

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000266-000272 ◽  
Author(s):  
Steven A. Morris ◽  
Jeremy Townsend
Keyword(s):  
Dielectric Constant ◽  
Temperature Dependence ◽  
Coupling Coefficient ◽  
Thin Disk ◽  
Piezoelectric Transducers ◽  
Parametric Models ◽  
Model Parameters ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Wide Range

Piezoelectric ultrasonic transducers are used extensively in well logging and logging-while-drilling applications for pulse-echo operation. We present a method of modeling the operation of ultrasonic thin-disk piezoelectric transducers over a wide range of temperatures. The model is based on using Redwood's version of Mason's model of thin-disk transducers. Laboratory measurements in the oven of non-backed transducers in air are used to extract the Mason model parameters as a function of temperature. Derived parameters are frequency-thickness constant, dielectric constant, and thickness mode coupling coefficient. A fourth parameter, bulk density, is measured independently and assumed constant over temperature. Temperature dependence of frequency thickness constant and coupling coefficient are modeled as linear temperature coefficients. Temperature dependence of the dielectric constant must be specified as a table because of the non-linear temperature dependence of that parameter.

Size and Temperature Dependence of Dielectric Constant of Ultrafine PbTiO 3 Particles

1994 ◽  
Vol 11 (8) ◽  
pp. 514-517 ◽  
Author(s):  
Baodong Qu ◽  
Bin Jiang ◽  
Yuguo Wang ◽  
Peilin Zhang ◽  
Weilie Zhong
Keyword(s):  
Dielectric Constant ◽  
Temperature Dependence

scholarly journals Protein Apparent Dielectric Constant and Its Temperature Dependence from Remote Chemical Shift Effects

2014 ◽  
Vol 136 (37) ◽  
pp. 12816-12819 ◽  
Author(s):  
Liaoyuan An ◽  
Yefei Wang ◽  
Ning Zhang ◽  
Shihai Yan ◽  
Ad Bax ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Chemical Shift ◽  
Temperature Dependence ◽  
Apparent Dielectric Constant

THE TEMPERATURE DEPENDENCE OF APPARENT DIELECTRIC CONSTANTS OF ADSORBATES ON NON-POROUS TITANIUM DIOXIDE

1957 ◽  
Vol 35 (12) ◽  
pp. 1534-1541 ◽  
Author(s):  
S. E. Petrie ◽  
R. McIntosh ◽  
E. W. Channen
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Temperature Dependence ◽  
Experimental Error ◽  
Adsorption Process ◽  
Porous Titanium ◽  
Dielectric Constants ◽  
Effect Of Temperature ◽  
Apparent Dielectric Constant

The temperature dependence of the apparent dielectric constants of various adsorbed polar gases on finely divided, non-porous titanium dioxide has been determined. Within the experimental error, the apparent dielectric constant of the material adsorbed in the monolayer is independent of temperature. The effect of temperature on the dielectric constant for gas adsorbed beyond the monolayer depends on the adsorbate. These results have been interpreted as indicating that molecules initially adsorbed are oscillators, while those adsorbed in later stages of the adsorption process may be rotators or oscillators.

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