AN INVESTIGATION OF SOME BARIUM TITANATE COMPOSITIONS FOR TRANSDUCER APPLICATIONS

1957 ◽  
Vol 35 (5) ◽  
pp. 594-607 ◽  
Author(s):  
D. Schofield ◽  
R. F. Brown
Keyword(s):  
Dielectric Loss ◽  
Barium Titanate ◽  
High Power ◽  
Large Reduction ◽  
Electroacoustic Transducer ◽  
Large Dielectric Loss ◽  
High Fields ◽  
Piezoelectric Constants

The most important factor limiting the use of barium titanate in high power electroacoustic transducer applications is the large dielectric loss in high exciting fields. It has been shown that the addition of cobalt to 5% calcium, 95% barium titanate compositions produces a large reduction in the loss in high fields without significantly affecting the piezoelectric constants of polarized ceramic.

An in situ (K0.5Na0.5)NbO3-doped barium titanate foam framework and its cyanate ester resin composites with temperature-stable dielectric properties and low dielectric loss

2019 ◽  
Vol 3 (4) ◽  
pp. 726-736 ◽  
Author(s):  
Longhui Zheng ◽  
Li Yuan ◽  
Guozheng Liang ◽  
Aijuan Gu
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Cyanate Ester ◽  
Resin Composites ◽  
Cyanate Ester Resin ◽  
Low Dielectric ◽  
Doped Barium Titanate

High-k composites with temperature-stable dielectric properties and low dielectric loss obtained through building a network with in situ-doped barium titanate foam.

Broadband Dielectric Spectroscopy Analysis of Dielectric Properties of Barium Titanate Ceramics

2013 ◽  
Vol 744 ◽  
pp. 323-328 ◽  
Author(s):  
Jie Yang ◽  
Xiang Yun Deng ◽  
Jian Bao Li ◽  
Qiang Cai ◽  
Hai Tao Zhang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Relaxation Model ◽  
Debye Relaxation ◽  
Broadband Dielectric Spectroscopy ◽  
Function Fitting ◽  
Loss Experience ◽  
Titanate Ceramics

The complex dielectric behaviors of ferroelectric barium titanate (BT) ceramics were investigated. The dielectric properties were studied as a function of temperature and frequency using broadband dielectric spectrometer. The results show that the maximum value of dielectric constant occurs at 500nm BT ceramics, which is approximately 7,500; the dielectric loss is lower than 0.03 with the temperature varying from 225 K to 450 K. Dielectric constant and dielectric loss experience three dielectric peaks corresponding to rhombohedral to orthorhombic, tetragonal and cubic transitions. With the frequency ranges from 1 MHz to 1 GHz, the dielectric relaxation is apparently present. The relaxation process obeys Cole-Cole relaxation model at high temperature and conforms to Debye relaxation model when the temperature far lower than Curie temperature. The relaxation time is the order magnitude of ~10-9s obtained by Havriliak-Negami function fitting, which is very consistent with theoretical calculation.

The Effect of Different Doping Methods of Sintering Aids on the Barium Titanate Based X7R Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 83-86 ◽  
Author(s):  
C. Ma ◽  
X.H. Wang ◽  
R.Z. Chen ◽  
Long Tu Li ◽  
Zhi Lun Gui
Keyword(s):  
Rare Earth ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Low Temperature ◽  
Rare Earth Oxide ◽  
Sintering Aids ◽  
Sintering Properties ◽  
Relationship Of ◽  
The Relationship

The barium titanate based X7R ceramics, which are doped with rare earth oxide, Nb2O5, Co3O4 and ZnO-B2O3, could be sintered at a rather low temperature to satisfy the X7R requirements with good permittivity and dielectric loss. In this paper, different doping methods of sintering aids have been used to prepare X7R BaTiO3 ceramics. Samples were sintered at a low temperature and the relationship of doping methods and sintering properties has been concluded.

scholarly journals The Structure and Properties of Electroceramics for Bone Graft Substitution

2007 ◽  
Vol 361-363 ◽  
pp. 99-102 ◽  
Author(s):  
F.R. Baxter ◽  
I.G. Turner ◽  
Chris R. Bowen ◽  
J.P. Gittings ◽  
J.B. Chaudhuri ◽  
...  
Keyword(s):  
Grain Size ◽  
Barium Titanate ◽  
Bone Growth ◽  
Piezoelectric Properties ◽  
Piezoelectric Effect ◽  
Positive Influence ◽  
Sem Analysis ◽  
A Value ◽  
Piezoelectric Constants

Hydroxyapatite (HA) and barium titanate (BT) powders were mixed and sintered to form hydroxyapatite – barium titanate (HABT) ceramics. These materials were then poled and their piezoelectric properties were measured. The microstructure of unpoled samples was examined using scanning electron microscopy (SEM).The piezoelectric constants (d33 and d31) of the ceramics were found to be dependent on the proportion of BT in the ceramic In materials containing less than 70% BT, no piezoelectric effect was found. Above this value, the piezoelectric constant increased with the addition of BT up to a value of 108pCN-1 for pure BT. Values of d33 for ceramics containing more than 80% BT are above values previously shown to have a positive influence on bone growth in vivo. SEM analysis indicated that the grain size within the materials decreased as the proportion of BT in the material was reduced. Examination of the microstructure of the ceramics indicated the presence of electrical domains in the 100% BT and 95% BT ceramics. Domains were not visible below 95% BT. The reduction in grain size may influence the reduction in piezoelectric activity within the materials but cannot be considered to be the only cause.

scholarly journals Effect of Multiple Substitutions (Pb, Ti, Zr) on Structural, Permittivity and Electrical Properties of BiFeO3 Ceramics

2017 ◽  
pp. 4810-4820
Author(s):  
Samita Pattanayak ◽  
Niranjan Panda ◽  
R N P Choudhary ◽  
Ashok Kumar
Keyword(s):  
Phase Transition ◽  
Dielectric Loss ◽  
Room Temperature ◽  
Conduction Mechanism ◽  
Electric Modulus ◽  
Electrical Parameters ◽  
Reaction Route ◽  
Large Dielectric Loss ◽  
Nyquist Plots ◽  
Diffuse Phase

Three complex polycrystalline samples of Bi1-xPbxFe1-x Zrx-yTiyO3,with the combination of (i) x, y = 0.0 (BFO), (ii) x = 0.5 and y = 0.5 (BFPTO)and (iii) x = 0.5 and y = 0.25 (BFPZTO) were prepared by a standard mixed oxide (solid state reaction route) method at optimized calcinations (900oC) and sintering (930-950oC)temperatures. The effect of multiple (Pb, Ti and/or Zr) substitutions of different amount onthe permittivity, impedance and modulus characteristics of the materials has been investigated at different frequencies and temperature.Limitation associated with BiFeO3 (BFO) due to its semiconducting behavior acts as constraint in polling the material at room temperature leading to large dielectric loss. Attempts were made to minimizethe loss by substitution of Pb on the Bi site and Ti and/or Zr at the Fe site of BFO. The study indicates that the phase transition temperature of BFO is lowered,the degree of diffuse phase transition is enhanced and electrical parameters (dielectric constant, electrical resistivity, remnant polarization and maximum polarization) areincreased with a significant reduction in dielectric loss as a consequence of the substitution. Detailed studies of Nyquist plots with impedance and electric modulus data suggest that the existence of non-Debye type of relaxation phenomena in the materials. The ac conductivity study reveals that the conduction mechanism in the material obeys universal Jonscher’s power law.

A New Type of Electroacoustic Transducer Used for Downhole Acoustic Telemetry System

2013 ◽  
Vol 336-338 ◽  
pp. 286-289
Author(s):  
Xuan Chao Liu ◽  
Yan Xia He ◽  
Guo Hong Li
Keyword(s):  
High Power ◽  
Acoustic Telemetry ◽  
Petroleum Industry ◽  
Low Frequency ◽  
Telemetry System ◽  
Magnetostrictive Materials ◽  
Electroacoustic Transducer ◽  
Giant Magnetostrictive Materials ◽  
Frequency Output ◽  
New Type

The high power and low frequency electroacoustic transducer plays a very important role in the underground acoustic telemetry system used for petroleum industry. How to realize electroacoustic conversion technology with the giant magnetostrictive materials was studied in this paper. The principles and methods of how to design it were proposed and the experimental verification was achieved. Results show that the electroacoustic transducer based on giant magnetostrictive materials features high-power and low-frequency output, high conversion efficiency, high temperature resistance, and excellent performance. It can completely meet the needs of the downhole acoustic telemetry system.

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