scholarly journals Effect of Ferroelectric Properties on Heat Treatment for Bi4-x+yLaxTi3O12-δ (x=0.5, y=0; x=0.75, y=0; x=0.75, y=0.15) Ferroelectric Ceramics

2004 ◽  
Vol 112 (1312) ◽  
pp. 669-673 ◽  
Author(s):  
Yasushi IDEMOTO ◽  
Naoto YOKOYAMA ◽  
Nobuyuki KOURA ◽  
Koichi UI
2007 ◽  
Vol 400 (1-2) ◽  
pp. 134-136 ◽  
Author(s):  
Jie Qiu ◽  
Guo-Zhen Liu ◽  
Meng He ◽  
Hao-Shuang Gu ◽  
Tao-Sheng Zhou

Author(s):  
Y Su ◽  
G.J Weng

Most key elements of ferroelectric properties are defined through the hysteresis loops. For a ferroelectric ceramic, its loop is contributed collectively by its constituent grains, each having its own hysteresis loop when the ceramic polycrystal is under a cyclic electric field. In this paper, we propose a polycrystal hysteresis model so that the hysteresis loop of a ceramic can be calculated from the loops of its constituent grains. In this model a micromechanics-based thermodynamic approach is developed to determine the hysteresis behaviour of the constituent grains, and a self-consistent scheme is introduced to translate these behaviours to the polycrystal level. This theory differs from the classical phenomenological ones in that it is a micromechanics-based thermodynamic approach and it can provide the evolution of new domain concentration among the constituent grains. It also differs from some recent micromechanics studies in its secant form of self-consistent formulation and in its application of irreversible thermodynamics to derive the kinetic equation of domain growth. To put this two-level micromechanics theory in perspective, it is applied to a ceramic PLZT 8/65/35, to calculate its hysteresis loop between the electric displacement and the electric field ( D versus E ), and the butterfly-shaped longitudinal strain versus the electric field relation ( ϵ versus E ). The calculated results are found to be in good quantitative agreement with the test data. The corresponding evolution of new domain concentration c 1 and the individual hysteresis loops of several selected grains—along with those of the overall polycrystal—are also illustrated.


2010 ◽  
Vol 1250 ◽  
Author(s):  
Indrani Coondoo ◽  
Neearj Panwar ◽  
Ashok Biradar ◽  
Arun Jha

AbstractTungsten (W)-substituted SBT ceramics [SrBi2(Ta1-xWx)2O9; 0.0 ≤ x ≤ 0.20] were synthesized by solid state reaction method using different sintering temperatures (1100 οC, 1150 οC, 1200 οC and 1250 οC). W substitution is found to significantly affect the electrical properties of SBT, including dielectric permittivity, Curie temperature, and ferroelectricity. Dielectric constant (εr) and the Curie temperature (Tc) increase with increasing W content. The dielectric loss reduces significantly with increase in W concentration. The maximum Tc of ~ 390 οC is observed in the sample with x = 0.20 as compared to ~ 320 οC for the pure sample when sintered at 1200 οC. The peak ε increases from ~ 270 in the sample with x = 0.0 to ~ 700 for the composition with x = 0.20, when sintered at 1200 οC. All the tungsten-substituted ceramics have higher 2Pr than that in the pristine sample. The maximum 2Pr (~25 μC/cm2) is obtained in composition with x = 0.05 sintered at 1200 οC. These effects have been interpreted based on the model of the recovery of oxygen vacancies upon W substitution. Such compositions with low loss and high Pr values should be excellent materials for highly stable ferroelectric memory devices.


2009 ◽  
Vol 54 (9(2)) ◽  
pp. 911-915 ◽  
Author(s):  
JinSoo Kim ◽  
SaesByul Kim ◽  
ByungChun Choi ◽  
JungHyun Jeong ◽  
YoungWoo No ◽  
...  

2016 ◽  
Vol 675-676 ◽  
pp. 509-512 ◽  
Author(s):  
Pichitchai Butnoi ◽  
Pratthana Intawin ◽  
Ploypailin Yongsiri ◽  
Nuttapon Pisitpipathsin ◽  
Puttapon Pengpad ◽  
...  

The ferroelectric ceramics with composition of (1-x)Pb(Zr0.52Ti0.48O3 [PZT] – x(Ba0.9Ca0.1)(Ti0.85Zr0.15)O3 [BCZT] (x = 0, 0.04, 0.08 and 0.10 ) have been successfully prepared via two-step mixed oxide method. The material systems of lead zirconate titanate (PZT) and barium calcium zirconate titanate (BCZT) have been intensive studied due to their remarkable properties of high ferroelectric and piezoelectric values. In this work, we are interesting to combine PZT with BCZT system in order to improve the electrical property of the ceramic samples. From the obtained results, it can be confirmed that ferroelectric values are significant increased with the optimum amount of the BCZT.


2009 ◽  
Vol 384 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Jin Soo Kim ◽  
Byung Chun Choi ◽  
Jung Hyun Jeong ◽  
Kwang-Sei Lee ◽  
Sang-Bock Cho

Author(s):  
Li-Wei Jin ◽  
Yu Su

In this work the coupled electromechanical behaviors of the overall properties of ferroelectric ceramics have been experimentally studied with different initial poling states and loading frequencies in order to have a better understanding of their domain switching mechanism. The material under investigation is soft PZT-5 ceramic, which shows noticeable nonlinear response upon externally applied load. The experimental results show that the state of initial poling in the specimens can evidently affect the characteristics of the hysteresis loops. The electrical loading frequency dependence of the ferroelectric properties of PZT-5, e.g., coercive field, remnant polarization, etc., has also been investigated through the tests conducted on the carefully designed multi-field testing system. Despite some common features of frequency dependence shared by all three types of initial poling, it is found out that the effects of loading frequency on the change of coercive field and remnant polarization for the specimen poled perpendicular to the switching axis deviate from those of the other two poling states, and this may be attributed to the specific domain switching mechanism for the perpendicularly poled specimen.


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