Ferroelectric and Dielectric Properties of La2O3-Doped BaTiO3 Ceramics

2011 ◽  
Vol 418-420 ◽  
pp. 721-725
Author(s):  
Yi Shan Wang ◽  
Xiang Yun Deng ◽  
Yan Jie Zhang ◽  
Ren Bo Yang ◽  
Li Ren Han ◽  
...  

The different concentration La2O3-doped BaTiO3 ceramics were prepared by sol-gel method. The ferroelectric and dielectric properties of the ceramics are characterized by TF analyzer 2000. With the increased amount of La2O3-doped, the dielectric constant increase gradually, when the sintering temperature is 1250 °C, the dielectric constant has reached 4648 for La2O3 with 0.4%-doped. With the temperature increased the dielectric constant of La-BaTiO3 increase gradually, when the sintering temperature is 1290 °C, the dielectric constant has reached 7066 for La2O3 with 0.4%-doped.

2011 ◽  
Vol 197-198 ◽  
pp. 302-305 ◽  
Author(s):  
Dong Xu ◽  
Chen Zhang ◽  
Xiao Nong Cheng ◽  
Yuee Fan ◽  
Tao Yang ◽  
...  

The CaCu3-xZnxTi4O12(CCZTO) (x=0, 0.06, 0.1, 0.2) ceramics were prepared by Sol–gel method. The XRD pattern shows that crystal structure of the sample with no Zn is basically single-phase. The SEM results indicate that the samples have porous structures and the gain size decreases with the content of Zn increasing. The dielectric properties of CCZTO were analyzed by Agilent 4294A. The experimental results show that the dielectric constants are less than that in other papers reported obviously because of their mesoporous structures. With the little doping amount(x=0.06, 0.1), a sharp decrease happened in the dielectric constant (εr). The higher εrwas found when x=0.2, but its dielectric loss (D) had greatly increased and frequency stability of dielectric property became worse. The uniformity of gains was put forward to explain the results which showed great impact on the dielectric constant.


2014 ◽  
Vol 8 (2) ◽  
pp. 101-108
Author(s):  
Nouara Lamrani ◽  
Ahcène Chaouchi ◽  
Jerôme Bernard ◽  
Brahim Itaalit ◽  
David Houivet ◽  
...  

In this work, we have studied the influence of lithium carbonate (Li2CO3) associated with the vanadium oxide (V2O5) on sintering and dielectrics properties of Ca0.5Sr0.5TiO3 ceramic materials obtained from nanopowder synthesized by sol-gel method. The nanopowder was obtained by controlled mixing of titanium butoxide dissolved in butanol-2 and acetic acid with a saturated aqueous solution of calcium acetate and strontium carbonate and subsequent drying of the formed gel at 80 ?C and calcination at 1100?C. The synthesized nanopowder was mixed with different amount of additives, and then uniaxally pressed and sintered in air atmosphere at temperature determined by dilatomertic measurements. The pure Ca0.5Sr0.5TiO3 sample obtained by this process required a sintering temperature around 1500?C. The addition of Li2CO3 combined with V2O5 improved sinterability and caused a shift of dilatimeric shrinkage curve to much lower temperatures. Thus, dense ceramics (98% of theoretical density) were obtained at sintering temperature ? 1300?C. The effect of adding Li2CO3-V2O5 on the structure of ceramics and the dielectric properties is discussed and show that type I dielectric properties (linear variation of the permittivity) are conserved, but with an increase of dielectric loss.


2007 ◽  
Vol 336-338 ◽  
pp. 76-78
Author(s):  
Jing Pei ◽  
Zhen Xing Yue ◽  
Fei Zhao ◽  
Zhi Lun Gui ◽  
Long Tu Li

The nano-sized Ba(Zr0.2Ti0.8)O3 powder was prepared by citrate sol-gel method. The crystal structure and the particle size of the powder were characterized by XRD. The morphology of calcined powder and the sintered ceramics was observed by TEM and SEM, respectively. The particle size of the powders calcined at 600oC is about 10 nm. The dense ceramics can be obtained at sintering temperature of 1220 oC, which is much lower than that of the powder prepared by the conventional solid method. The effects of Al2O3 additive on the sintering behavior, microstructure and dielectric properties of Ba(Zr0.2Ti0.8)O3 ceramics were also investigated.


2015 ◽  
Vol 740 ◽  
pp. 3-6
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Xin Jin ◽  
Wen Hong Tao ◽  
Yu Qin Qiang

KNN-BF piezoelectric ceramics synthesized by sol-gel method in this experiment. By controlling bismuth and iron content in the system to study effects of them. We selected citric acid as metal chelator and ethylene glycol as esterification agent. PH maintained 5-6 during preparation of the sol. Sintering temperature of ceramic selected 1100°C. Preparation ceramics under these conditions and comparative analysis, the structure of ceramics is single perovskite and shap of crystals are square block. With the increase of x, properties of ceramics firstly increases and then decreases: d33, εr, Qm, Kpreaching the maximum, values of them were 136pC/N, 630(f =1KHz), 212, 0.41 respectively; dielectric loss to minimum is 0.07(f =1KHz); at this point, ceramics had best performance.


2017 ◽  
Vol 520 (1) ◽  
pp. 75-82
Author(s):  
Hai Jiang ◽  
Xiao-Hong Wang ◽  
Jing Tao ◽  
Hua-Bo Wang ◽  
Fang-yuan Chen ◽  
...  

2015 ◽  
Vol 645 ◽  
pp. 171-177 ◽  
Author(s):  
Manish Srivastava ◽  
R.K. Mishra ◽  
Jay Singh ◽  
Neha Srivastava ◽  
Nam Hoon Kim ◽  
...  

1996 ◽  
Vol 433 ◽  
Author(s):  
Seong Jun Kang ◽  
Yung Sup Yoon ◽  
Dong Il Kim

AbstractWe have studied the pyroelectric properties of the PLT(10) thin film deposited on a p-doped poly-Si electrode by using the sol-gel method. Measurement of the dielectric constant as a function of temperature shows the typical characteristics of a ferroelectric. The dielectric constant reaches a maximum at 295°C, which can be thought of as the Curie temperature. The PLT(10) thin film on p-doped poly-Si fabricated in this research shows excellent pyroelectric properties. The pyroelectric coefficient and the fiqures of merit, Fv and FD at room temperature are measured as 5.76 × 10−8 C/cm2 °C, 1.17 × 10−10C-cm/J and 0.93 × 10−8C-cm/J, respectively.


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