Effect of Sr Doping on Piezoelectric Properties of Pb(Mn1/3Nb2/3)O3-Pb(Zr,Ti)O3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 201-204
Author(s):  
Bao Shan Li ◽  
Guo Rong Li ◽  
Zhi Gang Zhu ◽  
Wang Zhong Zhang ◽  
Qing Rui Yin ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Oxygen Vacancies ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Coupling Factor ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Pzt Ceramics

This paper aims at the determination of the effects of strontium addition on the microstructural evolution and the piezoelectric properties for Pb(Mn1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMnN-PZT) ceramics. The Sr content was chosen in the range of 2-8 mol%. These materials were prepared by the solid phase reaction of the oxides. It was found, from the experimental results, the tetragonality of the PMnN-PZT lattice and the Curie temperature decreased with Sr content; in the meantime, dielectric constant increased greatly. Dielectric constant (er) and planar coupling factor (Kp) was proven to be dependent on sintering temperature. P-E curves of PMnN-PZT system exhibited some “pinched” shape instead of the normal square-like P-E loops, illustrating presence of the oxygen vacancies by reason of the preferable substitution of the B-sites ion.

Effect of Sintering Temperatures and Ba/Ti Ratio on Dielectric Properties of BaTiO3 Ceramic

2013 ◽  
Vol 750-752 ◽  
pp. 506-511
Author(s):  
Yuan Yuan Li ◽  
Gui Xia Dong ◽  
Bi Yan Zhu ◽  
Qiu Xiang Liu ◽  
Di Wu
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Curie Temperature ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Method Effect

As a research object, the samples with various Ba/Ti ratios (Ba/Ti=0.95~1.05) were synthesized by solid phase reaction method. Effect of sintering temperatures and Ba/Ti ratio on dielectric properties and crystal structure of BaTiO3ceramic were investigated. Crystal structure and crystal phase composition were investigated by scanning electron microscopy and X-ray diffraction. The dielectric properties were studied by Agilent 4294A at 1 kHz. The results show that the BaTiO3ceramic has high permittivity and dielectric loss at 1340°C. The permittivity of BaTiO3ceramic with Ba/Ti=0.95 change small as the sintering temperatures vary at 1320°C. With the increasing of Ba/Ti ratio, the Curie temperature first increases and then decreases as the sample sintering at 1320°C. When Ba/Ti=1, the Curie temperature increase with the sintering temperature increasing.

Synthesis and Ionic Conductivity of KAlSi3O8

2016 ◽  
Vol 698 ◽  
pp. 8-12 ◽  
Author(s):  
Shinichi Furusawa ◽  
Yohei Minami
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Ionic Transport ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray

In this study, KAlSi3O8 was synthesized by a solid-phase reaction at 900, 1000 and 1100 °C, using K2CO3, Al2O3 and SiO2 as the starting materials. The powder X-ray diffraction profile of the compound thus prepared was confirmed to contain a mixture of crystalline and glass phases. In addition, a higher sintering temperature of greater than 1000 °C possibly led to the decrease in the crystalline phase. From the temperature dependence of dc conductivity, activation energies for ionic transport were estimated to be 0.79–0.84 eV. The frequency-dependence of the real part of electrical conductivity suggests that the mechanism of ionic transport in the dispersion region possibly depends on the crystallinity of KAlSi3O8.

Processing and Properties of Ferroelectric Bi4-x La xTi3O12 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 106-108
Author(s):  
Wen Wang ◽  
Hua Ke ◽  
Deng Guo Zhang ◽  
De Chang Jia ◽  
Yu Zhou
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Solid Phase ◽  
Sol Gel ◽  
Cold Isostatic Pressing ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Doping Content ◽  
La Doping ◽  
Reaction Processes

Bi4-xLaxTi3O12 (BLT, x=0, 0.75, 1, 2) ceramic powders were prepared with sol-gel and solid phase reaction processes, respectively. BLT powders were synthesized after decarbonization at 300°C for 1h followed by calcination at 800°C for 2h. The ceramics synthesized with cold isostatic pressing and sintering at 1150°C exhibit a perovskite-like structure. The influence of sintering parameters and La doping content on density, microstructure and dielectric properties of the BLT were discussed. With the increase of La doping content in Bi4-xLaxTi3O12, dielectric constant increases and dielectric loss gradually decreases. The dielectric constant and dielectric loss of Bi4-xLaxTi3O12 (x=2) are 132.7 and 0.012 at 100 KHz, respectively.

Ultrathin Dielectric Films Grown by Solid Phase Reaction of Pr with SiO2

2004 ◽  
Vol 811 ◽  
Author(s):  
Hans-Joachim Müssig ◽  
Jarek Dąbrowski ◽  
Christian Wenger ◽  
Grzegorz Łupina ◽  
Roland Sorge ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Solid Phase ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Dielectric Films ◽  
Solid Phase Reaction ◽  
Phase Reaction

ABSTRACTWe have fabricated Pr-based high-k gate dielectric films by physical vapor deposition of metallic Pr on SiO2 under ultra-high vacuum (UHV) conditions at room temperature, followed by oxidation and annealing steps. The films have been analyzed by electrical measurements, X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). Some insight into the physical processes involved has been obtained from ab initio calculations. The high-k gate stacks consist of a SiO2-based buffer with an enhanced dielectric constant and a Pr silicate barrier with a high dielectric constant. The role of the buffer is to preserve the high quality of the SiO2/Si(001) interface, and the role of the barrier is to keep the tunneling currents low by increasing its physical thickness. A Pr film deposited on a 1.8 nm SiO2 layer, oxidized at room temperature by air, and annealed in N2 atmosphere with O2 partial pressure of 10−3 mbar results in a stack with the Capacitance Equivalent Thickness of 1.5 nm and leakage of 10−4 A/cm2.

The Dielectric Characteristics of Sr and Mg Doped CCTO Ceramics

2011 ◽  
Vol 687 ◽  
pp. 416-421 ◽  
Author(s):  
Qiu Xiang Liu ◽  
Xin Gui Tang ◽  
Yan Ping Jiang ◽  
F. L. Dong
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Solid Phase ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Practical Applications ◽  
Complex Impedance Analysis ◽  
Mg Doped

Two kinds ceramics of pure CaCu3Ti4O12 (CCTO) and Sr/Mg doped (Ca0.25Cu0.75)0.5Sr0.5TiO3 + xMgO (x=0.01, 0.03, 0.05, 0.1, denoted as CCST-M-1, CCST-M-3, CCST-M-5, CCST-M-10, respectively) were prepared using the traditional solid phase reaction method. The dielectric properties were measured by HP 4194A Impedance/Gain-Phase Analyzer with the frequency range from 100 Hz to 1MHz. The temperature dependence of dielectric constant and loss tangent were measured for different frequencies. The variation relation of the critical temperature with the frequency was fitted theoretically which is in agreement with the Arrhenius law for pure CCTO. According to a variable power law to describe the paraelectric dielectric constant of ferroelectrics with diffuse phase transitions, the theoretical fitting was carried out for doped samples, and it was suggested that all doped samples exhibited the Debye-like relaxation. Among the doped and pure CCTO samples, CCST-M-1 was of the lowest dielectric loss at the whole measurement frequency, and whose I–V response curve was nonlinear suggesting a non-ohmic contact. The complex-impedance analysis results showed that the reduction in dielectric loss of CCST-M-1 sample can be attributed to the increase of grain boundary resistance. It is expect that these results are helpful to promote the CCTO-related materials to practical applications.

scholarly journals Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Solid Phase ◽  
Raw Materials ◽  
Phase Method ◽  
Maximum Adsorption Capacity ◽  
High Catalytic Activity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

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