Dielectric behavior of poled complex perovskite relaxor ferroelectrics

1997 ◽  
Vol 42 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Huiqing Fan ◽  
Zhuo Xu ◽  
Liangying Zhang ◽  
Xi Yao
Keyword(s):  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Complex Perovskite

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.

Contribution to the Dielectric Behavior of Relaxers from the Surface of Nano-Order Cluster in the Materials

1997 ◽  
Vol 492 ◽  
Author(s):  
Z. -Y. Cheng ◽  
Aqiang Guo ◽  
R. S. Katiyar
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Frequency Dependence ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Experimental Results ◽  
Time Analysis ◽  
Resonance Process

ABSTRACTBased on the analysis of the dielectric behavior of relaxor ferroelectrics, it is assumed that the material has two polarization processes. Thus, a formula, which can fit the experimental results very well, is proposed to describe the temperature and frequency dependence of the dielectric constant. The fitted results show that there is a resonance process in the material and the peak of the dielectric constant is determined with both the relaxation and resonance processes. The relaxation time analysis shows that the peak of the dielectric constant indeed consists of two parts.

Effect of Lanthanum-doping on the Dielectric Properties of Pb(Fe1/2Ta1/2)O3 Relaxor Ferroelectrics

2002 ◽  
Vol 17 (7) ◽  
pp. 1779-1784 ◽  
Author(s):  
W. Z. Zhu ◽  
M. Yan ◽  
P. Q. Mantas ◽  
J. L. Baptista ◽  
A. L. Kholkin
Keyword(s):  
Perovskite Phase ◽  
Frequency Dispersion ◽  
Xrd Analysis ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Lanthanum Doping ◽  
Charge Imbalance ◽  
La Doping ◽  
Lanthanum Content ◽  
One Step

This paper reports the influence of lanthanum-doping on the dielectric behavior of Pb(Fe1/2Ta1/2)O3 relaxor ferroelectrics, where the La ions are incorporated into the B-site of the perovskite constructing unit and the resultant charge imbalance is compensated by the presence of free charge carriers (holes). The formulated compositions were fabricated using one-step preparation method, and a nearly pure perovskite phase was attained, as verified by XRD analysis. Both the dielectric permittivity maximum (ε′max) and the temperature at which ε′max occurs (Tm) are progressively reduced by La-doping. The degree of frequency dispersion, however, is promoted, indicating the weakened ferroelectric couplings among the oxygen octahedra as a result of lanthanum incorporation. Moreover, the breadth of paraelectric to ferroelectric phase transition is broadened with an increase in lanthanum content, due to enhanced inhomogeneity and increase in the number of B-site cations. Frequency spectroscopy at a certain temperature below Tm reveals a widening of the size distribution of ferroelectric nanodomains, which is characteristic of relaxor microstructure, by La-doping.

Dielectric Behavior and Phonon Damping in Low-Dielectric Constant Perovskite Materials

1998 ◽  
Vol 511 ◽  
Author(s):  
Ram S. Katiyar ◽  
Igor Siny ◽  
R. Guo ◽  
A. S. Bhalla
Keyword(s):  
Raman Spectra ◽  
Charge Compensation ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Low Dielectric ◽  
Close Packed Structure ◽  
Crystal Fibers ◽  
Laser Heated

ABSTRACTWe have carried out a comparative study of the dielectric losses in some complex perovskites with both 1:1 and 1:2 compositions of the B ions, namely, SrAl1/2Nb1/2O3 (SAN), SrAl1/2Ta1/2O3 (SAT) and BaMg1/3Ta2/3O3 (BMT). The samples were prepared in two forms, viz. ceramics and single-crystal fibers, the latter were grown by laser heated pedestal growth technique (LHPG). All of these materials possess low dielectric constants, low losses and high Q values. In contrast to relaxor ferroelectrics, that as a rule exhibit broad features in their Raman spectra, SAN, SAT and especially BMT have very narrow phonon lines in the Raman spectra. A linear correlation is found between the microwave dielectric losses and the width of first order phonon lines in a sequence of BMT → SAT → SAN ceramics with increasing phonon damping. Moreover, the phonon damping decreases in materials with non-close-packed structure where there is enough space for undisturbed phonon vibrations. The problem of charge compensation in compounds with the Bsite disorder is also discussed.

scholarly journals Dielectric behavior of spark plasma sintered BaTi0.7Zr0.3O3 relaxor ferroelectrics

2019 ◽  
Vol 15 ◽  
pp. 102799
Author(s):  
Mohamad M. Ahmad ◽  
Latifah Alismail ◽  
Adil Alshoaibi ◽  
Abdullah Aljaafari ◽  
H. Mahfoz Kotb ◽  
...  
Keyword(s):  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Spark Plasma

The Debye Dielectric Behavior of Mixed Normal and Relaxor-Ferroelectrics: Monte Carlo Investigation

2010 ◽  
Vol 401 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Yongyut Laosiritaworn ◽  
Kanokwan Kanchiang ◽  
Athipong Ngamjarurojana ◽  
Rattikorn Yimnirun ◽  
Ruyan Guo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Monte Carlo Investigation
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