scholarly journals Anisotropic Ferro- and Dielectric Properties of Textured Bi4Ti3O12Ceramics Prepared by the Solid-State Reaction Based on Multiple Calcination

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Xiangyu Mao ◽  
Wei Wang ◽  
Hui Sun ◽  
Xiaobing Chen

The grain-oriented Bi4Ti3O12(BIT) samples were prepared by the solid-state reaction method with a multicalcination process. The grain-oriented BIT samples exhibit anisotropic structural, ferroelectric, piezoelectric, and dielectric properties. The remanent polarization (2Pr) and the piezoelectric constant (d33) ofa/b- andc-direction BIT ceramics are 49.5 μC cm−2, 22.2 pC N−1and 6.7 μC cm−26.9 pC N−1, respectively. The dielectric anomalies of samples are observed around 157 K and 232 K. The dielectric anomalies at around 157 K are related to oxygen vacancies. The activation energy of the dielectric relaxation of this anomaly is estimated to be 1.36 eV. Another dielectric anomaly at around 232 K is related to polarizable domains and the viscous motion of domain walls.

2019 ◽  
Vol 13 (2) ◽  
pp. 164-172
Author(s):  
Rashmi Negi ◽  
Mallam Chandrasekhar ◽  
Pavan Kumar

(1-x)BaTiO3-xCaCu3Ti4O12 ceramic powders (where x = 0, 0.02, 0.04, 0.06, 0.08 and 1) were synthesized by solid state reaction method and sintered at up to 1250?C. Phase formation, elemental composition and microstructure of all the samples were investigated by XRD, EDX and FESEM, respectively. The BT-CCTO ceramic samples corresponding to x = 0.04 content showed the best dielectric properties. The improvement of dielectric properties was attributed to the presence of oxygen vacancies. Ferroelectricity was retained for CCTO content up to x = 0.06.


2007 ◽  
Vol 336-338 ◽  
pp. 272-274
Author(s):  
S.S. Cheng ◽  
J. Luo ◽  
Zhao Xian Xiong

Microwave ceramics of Ba(Mg0.2/3Zn0.8/3Nb2/3)O3 and Ba1-xSrx(Mg0.2/3Zn0.8/3Nb2/3)O3 were synthesized with conventional solid-state reaction method. Dielectric properties of the samples were studied as functions of compositions and sintering temperatures. Experimental results show that a higher Q×f value is reached by substituting Zn ions with Mg ions and a near-zero temperature coefficient of resonant frequency is obtained by replacing Ba ions with Sr ions.


2013 ◽  
Vol 675 ◽  
pp. 200-204
Author(s):  
Fei Shi ◽  
Peng Cheng Du ◽  
Jing Xiao Liu ◽  
Ji Wei Wu ◽  
De Qing Chen ◽  
...  

The Mg2SiO4-MgTiO3-CaTiO3 composite dielectric ceramics with different Mg2SiO4 addition amounts were prepared by solid state reaction method. The effects of Mg2SiO4 addition amounts on the microstructure and dielectric properties as well as sintering temperature of xMg2SiO4-(0.95-x)MgTiO3-0.05CaTiO3 (abbreviated as xMSTC, 0.25≦x≦0.75) composite ceramics were investigated. The results indicated that the sintering temperature of MgTiO3-CaTiO3 based ceramics with Mg2SiO4 addition could be lowered effectively to 1320~1340°C, and the dielectric constant decreased and dielectric loss increased gradually with the increase of Mg2SiO4 content. The 0.45MSTC ceramics containing 45 wt% Mg2SiO4 and sintered at 1340°C showed desirable dielectric properties with dielectric constant εr=13.3,dielectric loss tanδ=4.5×10-4 and temperature coefficient of relative permittivity τε =10 ppm/°C.


2008 ◽  
Vol 368-372 ◽  
pp. 129-131
Author(s):  
Yong He ◽  
Ke Pi Chen ◽  
Dong Yu Liu ◽  
Zong De Liu

CaCu3(Ti1-xZrx)O12 ceramics (x = 0.02, 0.04, 0.06, 0.08) were prepared by the conventional solid-state reaction method. Phase compositions, microstructure and dielectric properties were examined by XRD, SEM and impedance spectroscopy, respectively. The experimental results indicated that there is no obvious effect on microstructure characteristic by substituting Zr4+ for Ti4+. It was found that the values of the dielectric constant for all of the samples dropped into the order of 102, which is significantly lower than the order of 105 that of normally reported in the literature. It was suggested that the presence of impurity phases played an important role for the degeneracy of dielectric properties.


RSC Advances ◽  
2014 ◽  
Vol 4 (87) ◽  
pp. 46704-46709 ◽  
Author(s):  
Xuzhong Zuo ◽  
Jie Yang ◽  
Bin Yuan ◽  
Dongpo Song ◽  
Xianwu Tang ◽  
...  

The n = 5 Aurivillius phase ceramics Bi6Fe2−xMnxTi3O18 (BFMTO) (0 ≤ x ≤ 0.8) were synthesized with a conventional solid-state reaction method.


2012 ◽  
Vol 549 ◽  
pp. 749-752
Author(s):  
Hai Tang Hua ◽  
Xin You Huang ◽  
Zhi Wen Zhu ◽  
Yin Qun Hua ◽  
Yan Li

(Bi2-xLix) (Mg2/3Nb1.1833Sn0.15)O7 piezoelectric ceramics were prepared by conventional solid state reaction method. The microstructure and dielectric properties of dielectric ceramics were studied which was doped by different amount of Li2CO3. The experiment results showed that the density of the ceramics would decrease, but have little effect on the microstructure of the ceramics when the amount of the Li2CO3 doped increases. With the increasing of Li2CO3 doped, the dielectric constant(εr) and dielectric loss(tanδ) of dielectric ceramics first decreases and then increases. When tested in 1MHz frequency, the piezoelectric ceramics display the optimum properties tanδ is 0.00009, εr is 163 while Li2CO3 doped amount is 0.05 mol%.


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