Influence of La2O3 Doping Amount on Properties of NBT-KBT-BT Lead-Free Piezoelectric Ceramics

2010 ◽  
Vol 43 ◽  
pp. 614-618
Author(s):  
Xin You Huang ◽  
Chun Hua Gao ◽  
Min Xian Wei ◽  
Zhi Gang Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Perovskite Phase ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Doping Amount ◽  
Sem Images ◽  
Solid State Method ◽  
Piezoelectric Strain ◽  
Piezoelectric Strain Constant

0.85(Na0.5Bi0.5)TiO3-0.144(K0.5Bi0.5)TiO3-0.006BaTiO3(NBT-KBT-BT) lead-free piezo -electric ceramics were prepared using conventional solid state method. The influence of La2O3 doping amount on the crystal phase, surface microstructure and properties of the NBT-KBT-BT lead free piezoelectric ceramics were investigated using X-ray diffraction(XRD), Scanning electron microscopy(SEM) and other analytical methods. The results show that La2O3 has diffused into the lattice of NBT-KBT-BT ceramics. Consequently, a pure perovskite phase is formed. SEM images show that the microstructure of the ceramics is changed with the addition of a small amount of La2O3, La2O3 doping can make grain growing. The piezoelectric strain constant(d33) starts increasing and then decreasing, the dielectric constant(εT33/ε0) increases continuously and the dielectric loss(tanδ) starts increasing and then decreasing and then increasing when La2O3 doping amount increases. When the doping amount of La2O3 is 0.4wt.% and the sintering temperature is 1160°C, the NBT-KBT-BT piezoelectric ceramics with good comprehensive properties can be obtained. Its piezoelectric strain constant(d33), dielectric constant(εT33/ε0), and dielectric loss(tanδ) are 151pC/N, 1543 and 4.2%, respectively.

Effects of Sr and Mn-Doping on the Electrical Properties of CaBi4Ti4O15-Based Ceramics

2013 ◽  
Vol 575-576 ◽  
pp. 494-498 ◽  
Author(s):  
Bin Fu ◽  
Yang Lu Hou ◽  
Ting Li ◽  
Xing Hua Fu
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Perovskite Phase ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Piezoelectric Constant ◽  
Crystal Phase ◽  
Mn Doping ◽  
Mn Doped

Lead-free Sr-and Mn-doped Ca1-xSrxBi4Ti4O15, Ca1-yMnyBi4Ti4O15 bismuth layer piezoelectric ceramics have been prepared. The microstructure and electrical properties of the products were studied by XRD, SEM and Broadband LRC digital bridge. The obtained ceramics have Bi-layer perovskite phase. The dopings do not change the crystal phase of CaBi4Ti4O15. However, the doping amounts affect the size of crystal grain and porosity of the final products. The appropriate amounts of dopings for obtaining the highest dielectric constant and the lowest dielectric loss are determined. The prepared ceramics show the largest piezoelectric constant of 5.2~5.3 pC/N with the optimal Sr-and Mn-dopings.

Effect of Al2O3 and MgO Additives on Dielectric Properties of BaZrxTi1-xO3-Based Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 714-718
Author(s):  
Hong Jun Feng ◽  
Hui Ming Ji ◽  
Xiao Lei Li ◽  
Jian Wang ◽  
Da Hao Wang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Raw Materials ◽  
Bias Field ◽  
Phase Shifters ◽  
Sem Images ◽  
Solid State Method ◽  
Tunable Capacitors ◽  
Lcr Meter

BaZrxTi1-xO3-based (BZT) ceramics with Al2O3 and MgO addtives were prepared by the conventional solid state method with BaCO3, ZrO2, TiO2, Al2O3 and MgO as raw materials and B2O3 and Li2CO3 as sintering additive. The morphologies were analysized by scanning electron microscopy (SEM). The dielectric constant and dielectric loss of ceramics were measured by LCR meter. The temperature dependences of dielectric constant were measured by high-low temperature incubator tank and LCR meter at 1 MHz and a temperature range-55 to 125 °C. The tunabilities were tested by C-T-V converter and LCR meter at 1 MHz at room temperature. The results show that with the increase of Zr/Ti, BZT ceramic dielectric constant increases, the loss increases, the Curie temperature moves to a lower temperature, and dielectric bias field coordination is relatively lower. The SEM images show that the grain size reaches about 1-2 μm when the sintering temperature is 1100 °C, and the addition of Al2O3 and MgO promote the grain growth and densification of the composite ceramics. The Curie peaks are broadened and depressed with the addition of Al2O3 and MgO. The tunability is improved to 9.59% under a DC electric field of 7.0 kV/cm after the addition of Al2O3. The dielectric constant and dielectric loss of BaZr0.25Ti0.75O3-30wt%Al2O3 and BaZr0.25Ti0.75O3-30wt%MgO are 586, 0.011 and 486, 0.003, respectively. The optimistic dielectric properties make it a promising candidate for the application of tunable capacitors and phase shifters.

Study on Ce and La Doped 0.85NBT-0.144KBT-0.006BT Lead-Free Piezoelectric Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 2663-2666
Author(s):  
Xin You Huang ◽  
Chun Hua Gao ◽  
Zhi Gang Chen
Keyword(s):  
Crystal Structure ◽  
Grain Growth ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
Pure Perovskite Structure ◽  
Solid States ◽  
Piezoelectric Strain ◽  
La Doped

0.85(Na0.5Bi0.5)TiO3-0.144(K0.5Bi0.5)TiO3-0.006BaTiO3(0.85NBT-0.144KBT-0.006BT) lead-free piezoelectric ceramics was prepared by conventional ceramic technique. The influence of La2O3 doping amount and CeO2 doping amount on properties , crystal structure and surface topography of 0.85NBT-0.144KBT-0.006BT ceramics were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and other analytic methods. It shows that all compositions show the characteristics of pure perovskite structure solid states, La2O3 and CeO2 doping only changes crystal cell dimension rather than crystal structure. The piezoelectric strain constant (d33) starts increasing and then decreasing, the dielectric constant (εT33/ε0) increases, the dielectric loss (tanδ) starts increasing and then decreasing and then increasing while La2O3 doping amount increasing. d33 and εT33/ε0of ceramics starts increasing and then decreasing, tanδ decreases while CeO2 doping amount increasing . When the La2O3 doping amount is up to 0.4 wt.%, the doped samples show good performances with d33=151 pC/N, εT33/ε0=1543 and tanδ=4.3%. When the CeO2 doping amount is 0.1 wt.%, the doped samples show good performances with d33=156 pC/N, εT33/ε0=1364 and tanδ=3.8%. La2O3 doping promotes crystal grain growth, CeO2 doping makes grain crystal size uniform, changes tetragonal into granular structure and restrains crystal grain growth.

KNN-BF Lead-Free Piezoelectric Ceramics Synthesized by Sol-Gel Method

2015 ◽  
Vol 740 ◽  
pp. 3-6
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Xin Jin ◽  
Wen Hong Tao ◽  
Yu Qin Qiang
Keyword(s):  
Comparative Analysis ◽  
Citric Acid ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Chelator

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.

A high temperature stable piezoelectric strain of KNN-based ceramics

2018 ◽  
Vol 6 (41) ◽  
pp. 19967-19973 ◽  
Author(s):  
Zhenyong Cen ◽  
Yu Huan ◽  
Wei Feng ◽  
Yan Yu ◽  
Peiyao Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Piezoelectric Strain

Lead-free (1 − x)(0.96K0.46Na0.54Nb0.98Ta0.02O3–0.04Bi0.5(Na0.82K0.18)0.5ZrO3)–xCaZrO3 ((1 − x)(0.96KNNT–0.04BNKZ)–xCZ) piezoelectric ceramics were prepared by the conventional solid-state reaction method.

Dielectric and Piezoelectric Properties of Lead Free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 Piezoelectric Ceramics

2011 ◽  
Vol 492 ◽  
pp. 194-197 ◽  
Author(s):  
Yue Fang Wang ◽  
Xiu Jie Yi ◽  
Wei Pan ◽  
Guo Zhong Zang ◽  
Juan Du
Keyword(s):  
Electrical Properties ◽  
Dielectric Loss ◽  
Phase Structure ◽  
Perovskite Structure ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Compositional Dependence ◽  
Pure Perovskite Structure ◽  
Dielectric And Piezoelectric Properties

Lead-free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 ceramics were synthesized by ordinary sintering technique. The compositional dependence of phase structure and electrical properties of the ceramics was systematically investigated. All samples possessed pure perovskite structure. The dielectric and piezoelectric properties of ceramics were investigated with the amount of different BiFeO3 substitutions. The addition of BiFeO3 can not only decrease Ec and Pr but also lead to a significant degradation of the dielectric loss tanδ.

Effects of Barium Substitution on the Structure and Properties of PSZT Piezoelectric Ceramics

2010 ◽  
Vol 650 ◽  
pp. 103-108
Author(s):  
Yu Hua Feng ◽  
Tie Zheng Pan ◽  
Xiang Qian Shen ◽  
Hao Jie Song ◽  
Li Ping Guo
Keyword(s):  
Curie Temperature ◽  
Structural Changes ◽  
Piezoelectric Properties ◽  
Relative Dielectric Constant ◽  
Piezoelectric Ceramics ◽  
X Ray Diffraction ◽  
Piezoelectric Strain ◽  
High Dielectric ◽  
Dielectric And Piezoelectric Properties ◽  
Piezoelectric Strain Constant

Piezoelectric ceramics with appropriate curie temperatures and high dielectric and piezoelectric performances are attractive for formations of ceramic/polymer piezoelectric composites. The PSZT ceramics with compositions of 0.98Pb1.0-xBaxTi0.48Zr0.52O3-0.02PbSbO3 (x=0.14~0.24) have been prepared by a conventional solid reaction process. The ceramic structures are analyzed by X-ray diffraction and the barium substitution leads to structural changes of the tetragonal and rhombohedral phases which constitute the perovskite PSZT ceramics, and lattice distortions. The curie temperature almost linearly decreases from 226 °C to 141 °C corresponding the barium content increases from 0.14 to 0.24 in the ceramics. The dielectric and piezoelectric properties are largely influenced by the barium substitution and when the barium content at vicinity of 0.22, the piezoelectric strain constant d33 exhibits a dramatic change. It is found that as the barium content around 0.22, the PSZT ceramic specimen is characterized with a low curie temperature Tc=156 °C, and satisfied dielectric and piezoelectric properties with the relative dielectric constant εr=5873, dielectric loss factor tanδ=0.0387, piezoelectric strain constant d33=578 pC/N.

Giant dielectric constant and high-temperature dielectric relaxation properties in La-doped SrTiO3 ceramics

2020 ◽  
pp. 2150046
Author(s):  
Tianyang Liu ◽  
Xiaofei Wang ◽  
Congcong Li ◽  
Bowen Shen ◽  
Mingyan Yao ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Temperature Region ◽  
Relaxation Processes ◽  
Doping Amount ◽  
Solid State Method ◽  
Giant Dielectric ◽  
Region I ◽  
Giant Dielectric Constant ◽  
Region Ii

[Formula: see text] (SLTO) ceramics ([Formula: see text] = 0.05, 0.10, 0.15) were prepared with giant dielectric constant by the traditional solid-state method at 1350[Formula: see text]C. The temperature dependence of the dielectric constant was obtained at the temperature ranging from 29[Formula: see text]C to 500[Formula: see text]C and the frequency ranging from 2 kHz to 2 MHz. Two sets of relaxation peaks appear in the low temperature (region I) and the high temperature (region II), respectively. For region I, we conclude that the relaxation behavior is related to the oxygen vacancy migration. For region II, the two relaxation processes are caused by grain boundary for high frequency and Sr or Ti defects at grain interior for low frequency. With the doping amount reaching 0.15, the relaxation peaks disappear and become a common phase transition because of the aggravation of lattice distortion. These possible physical mechanisms of two sets of relaxation peaks are briefly discussed.

Dielectric Properties of Li-Doped CaCu3Ti4O12 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 251-256 ◽  
Author(s):  
Ying He ◽  
Huai Wu Zhang ◽  
Yuan Xun Li ◽  
Wei Wei Ling ◽  
Yun Yan Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Secondary Phase ◽  
Doping Amount ◽  
Spectroscopy Analysis ◽  
Low Dielectric ◽  
Tan Δ ◽  
High Dielectric ◽  
Impedance Spectroscopy Analysis

CaCu3Ti4O12 ceramics doped with 0-2.0 wt% Li2CO3 were prepared by the solid-state reaction, and their electric and dielectric properties were investigated. It is found that these ceramics had the properties of high dielectric constant and comparatively low dielectric loss. At the doping amount of 0.5 wt%, the dielectric constant is kept to be 105 with weak frequency dependence below 105 Hz, and its loss tangent (tan δ) is suppressed below 0.1 between 300 Hz-5 kHz (with the minimum value of 0.06 at 1 kHz from 218 K to 338 K). The impedance spectroscopy analysis confirms that the decrease of dielectric loss is mainly due to the increase of resistance in the grain boundary, which may be related to the influence of Ti4O7 secondary phase. Our result indicates that doping Li2CO3 is an efficient method to optimize the dielectric properties of CaCu3Ti4O12.

Influence of Ti content and sintering temperature on dielectric properties of Bi4Ti3O12 ceramics

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744057 ◽  
Author(s):  
Yong Chen ◽  
Zhaozhi Li ◽  
Huyin Su ◽  
Simin Xue ◽  
Mengyun Bian ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Curie Temperature ◽  
Relative Permittivity ◽  
Dielectric Material ◽  
Perovskite Phase ◽  
Layered Perovskite ◽  
Microwave Ceramics ◽  
Ti Content

An ultra-broad working temperature dielectric material, Bi4Ti[Formula: see text]O[Formula: see text]([Formula: see text] = 2.96, 2.98, 3.0, 3.02 and 3.04), prepared by a conventional mixed oxide route was investigated which is supposed to replace lead-containing ceramics for its outstanding dielectric properties. Microstructure and dielectric properties of well-sintered samples (at 1040[Formula: see text]C, 1060[Formula: see text]C, 1080[Formula: see text]C, 1100[Formula: see text]C and 1120[Formula: see text]C) were studied. X-ray diffraction analysis indicated that the new material was in a single Bi-layered perovskite phase. The dielectric constant and dielectric loss at different frequencies (10, 100 and 1000 kHz) were measured at 1100[Formula: see text]C. With the increasing frequency, the dielectric constant decreased and the dielectric loss was almost unchanged. While at 100 kHz, there is the highest relative permittivity ([Formula: see text]) of 2822.8 and the lowest dielectric loss of 0.0040 ([Formula: see text] = 2.98), the Curie temperature ([Formula: see text]) is 668.9[Formula: see text]C. At the frequency of 1 MHz, the highest relative permittivity ([Formula: see text]) is 1115.8 when Ti content is 3.02, and the Curie temperature is 672.2[Formula: see text]C. SEM can explain the results of the dielectric spectrum at different Ti content and sintering temperatures. [Formula: see text] plots show that Bi4Ti3O[Formula: see text] ceramics are a kind of dielectrics. Since it possesses large dielectric constant, low dielectric loss and stable temperature character, this material shows promising applications for the ultra-broad temperature range components, such as high-temperature multilayer ceramic capacitors and microwave ceramics.

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