Effects of thermal annealing on the dielectric properties of Pb(Zn1/3Nb2/3)O3-based ceramics

1999 ◽  
Vol 14 (5) ◽  
pp. 1683-1685 ◽  
Author(s):  
Feng Xia ◽  
Xi Yao
Keyword(s):  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Thermal Annealing ◽  
Wall Motion ◽  
Relative Dielectric Constant ◽  
Domain Wall Motion ◽  
Dissipation Factor ◽  
Diffusion Factor ◽  
Maximum Dielectric Constant

Pb(Zn1/3Nb2/3)O3-based ceramics were thermally annealed at 700–900 °C for 4 h. Both the relative dielectric constant and dissipation factor in the vicinity of transition temperature were increased when the specimens were thermally annealed at 700–900 °C, but the diffusion factor was decreased. After thermal annealing, the maximum dielectric constant Km was increased from about 11,000 to 26,000. These phenomena can be related to the domain wall motion and the elimination of internal stress.

Sintered compacts of nano and micron-sized BaTiO3: Dramatic influence on the microstructure and dielectric properties

2006 ◽  
Vol 21 (4) ◽  
pp. 816-822 ◽  
Author(s):  
Vishnu Shanker ◽  
Tokeer Ahmad ◽  
Henry Ip ◽  
Ashok K. Ganguli
Keyword(s):  
Differential Scanning Calorimetry ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
High Dielectric Constant ◽  
Scanning Calorimetry ◽  
Ferroelectric Transition ◽  
Maximum Dielectric Constant ◽  
High Dielectric ◽  
First Time

Sintered compacts of nano-sized and micron-sized BaTiO3 show sharp ferroelectric transition and high dielectric constant at specific compositions. The sintered compacts with 1 wt% nano-BaTiO3 show a maximum dielectric constant of 1680. At the transition temperature (Tc) there are two maxima at 0.5 and 2 wt%. The variation in the dielectric constant at Tc is also reflected in the behavior of the ferroelectric transition as studied by differential scanning calorimetry. This interesting oscillatory variation of the dielectric constant and dielectric loss with increase in the amount of nanoparticles in the sintered compacts is observed for the first time. The variation of the dielectric properties and the ferroelectric transition of the sintered compacts could be related to subtle changes in the microstructure.

The Microstructure and Dielectric Properties of SrTiO3 Modified 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 433-438
Author(s):  
Jing Song Liu ◽  
Tao Li ◽  
Hui Qin Li ◽  
You Chao Xu ◽  
Ji Qiang Yu
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Spontaneous Polarization ◽  
Relaxor Behavior ◽  
Maximum Dielectric Constant ◽  
Lower Temperature ◽  
Region Size ◽  
Maximum Permittivity

The microstructure and dielectric properties of ferroelectric solutions which is formulated with (1-x)[0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3]-x mol% SrTiO3(x=0, 1, 3 and 5) have been investigated. The ceramics was fabricated by a modified columbite route sintered at 1200 °C. The effects of dopants on microstructure, maximum dielectric constant (εm) and diffuseness of the phase transition, etc. have been studied. It is found that the maximum permittivity (εm) increases to 24968 for the ST-doped (1 mol %) sample, subsequently decreases with ST addition and its corresponding phase-transition-temperature (Tm) shifts to the lower temperature. The variation of εmis caused by the decrease of polar nano-region size, increase of the fluctuation of the component and the increase of the effective spontaneous polarization. The enhancement of relaxor behavior in the PMN-PT sample is explained by the decrease of FE/AFE coupling.

The Research on the Piezoelectric and Dielectric Properties of Bi0.5(Nak)0.5-BaTiO3 Lead-Free Ceramics

2014 ◽  
Vol 1035 ◽  
pp. 422-425
Author(s):  
Jian Yong Guo ◽  
Tao Sheng Zhou ◽  
Ji Hong Liao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Lead Free ◽  
Reactive Sintering ◽  
Lead Free Ceramics ◽  
Xrd Patterns ◽  
Sintering Method

The Bi0.5(Na1-xKx)0.5-yBaTiO3(BNK-BT) lead-free ceramics have been prepared by the solild reactive sintering method. XRD patterns show the BNK-BT ceramics had a perovskite structure. Piezoelectric and dielectric properties of the ceramics also have been studied. The results show that the samples had the best piezoelectric and dielectric properties when x=0.20, y=0.10. And the maximum of d33is 149 pC/N, while the relative dielectric constant is 1087.

Kinetic Study of Portland Cement Hydration with Ground Penetrating Radar

2013 ◽  
Vol 539 ◽  
pp. 25-29
Author(s):  
Wei Chen ◽  
Pei Liang Shen ◽  
Jian Xin Lu ◽  
Wan Ru Zhang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Ground Penetrating Radar ◽  
Cement Hydration ◽  
Relative Dielectric Constant ◽  
Gradual Decline ◽  
Hardening Process ◽  
Ground Penetrating ◽  
Kinetics Of ◽  
Portland Cement Hydration

The variations of dielectric constant and the amplitude of reflected EM wave of concrete during the first 3 days are measured with Ground Penetrating Radar (GPR) at 20 oC. The amplitude decreases sharply after mixing with water, and then increases till a stabilized stage, followed by a gradual decline. The relative dielectric constant decreases with increasing hydrating time. The results show that the dielectric properties of concrete can be used as an effective way of studying the kinetics of concrete setting and hardening process at early ages.

Bismaleimide/Allylnadic-Imide Blends Yield Low Dielectric Constant And Low Water Uptake

1991 ◽  
Vol 227 ◽  
Author(s):  
J-PH Ansermet ◽  
A. Kramer
Keyword(s):  
Dielectric Constant ◽  
Glass Transition ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Water Uptake ◽  
Water Saturation ◽  
Low Dielectric Constant ◽  
Aliphatic Chain ◽  
Bismaleimide Resin ◽  
Low Dielectric

ABSTRACTThe bismaleimide resin Matrimid 5292A (I) was cocured with an allylnadic-imide resin (EP 433) which contained a long aliphatic chain as backbone (II). Water uptake, swelling, and the dielectric properties (up to 300 MHz) were studied in cast plates. The dielectric constant varied from 5.4 in (I) to 3.2 in (II) at water saturation, compared to 3.1 in (I) to 2.7 in (II) in the dry state. The glass transition temperature stayed above 200 °C at less than 80 mol% of (II).

STUDIES ON ORIENTED DOMAIN POLYSTYRENE-TGS COMPOSITE FILMS

1995 ◽  
Vol 09 (17) ◽  
pp. 1039-1044
Author(s):  
S.C. MATHUR ◽  
D.S. RAWAT ◽  
H.O. YADAV ◽  
D.C. DUBE ◽  
A.S. BHALLA
Keyword(s):  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Domain Structure ◽  
Spontaneous Polarization ◽  
Coercive Field ◽  
Composite Films ◽  
Microwave Frequency ◽  
Ferroelectric Films ◽  
Microwave Frequencies

Polymer ferroelectric films were prepared by dispersing TGS powder in polystyrene. Permittivity versus temperature plots exhibit a peak at around the transition temperature of TGS. The peak gets suppressed with increasing frequency and the trend continues up to microwave frequencies. We observed that the dielectric constant of films at microwave frequency stays close to the dielectric constant of polystyrene. The domain structure of TGS crystals essentially seems to affect their dielectric properties. Single domain films exhibit a higher spontaneous polarization and a higher coercive field.

The effect of Ag electrode processing on (Nb, Ba) doped TiO2 ceramics

1990 ◽  
Vol 5 (7) ◽  
pp. 1530-1537 ◽  
Author(s):  
Chi-Jen Chen ◽  
Jenn-Ming Wu
Keyword(s):  
Dielectric Properties ◽  
Processing Condition ◽  
Temperature Stability ◽  
Relative Dielectric Constant ◽  
Dissipation Factor ◽  
Interface Layer ◽  
X Ray Diffraction ◽  
Ag Electrode ◽  
Ag Paste ◽  
Interface Layers

Since the characteristics of the electrode made from Ag paste greatly affect the dielectric properties of (Nb, Ba) doped TiO2 ceramics, the processing condition, i.e., baking temperature, was investigated. Low melting glass binder contained in Ag paste reacted with TiO2 ceramics to form an interface layer between Ag electrode and TiO2 ceramics during baking. The interface layer was identified as Bi2Ti2O7 by x-ray diffraction (XRD), and the thickness of the Bi2Ti2O7 layer was estimated from line profiles of EPMA and dielectric properties. The interface layers were found to increase with baking temperature. Increased baking temperature lowered the relative dielectric constant and dielectric dissipation factor of TiO2 ceramics, while it raised the resistivity. Controlling the baking condition of the Ag paste electrode on TiO2 ceramics resulted in reasonably good dielectric properties and excellent temperature stability.

Effect of the Annealing Temperature on Dielectric Properties of Bi1.5Zn1.0Nb1.5O7 Films Prepared by MOCVD

2008 ◽  
Vol 388 ◽  
pp. 175-178
Author(s):  
Hiroshi Funakubo ◽  
Shingo Okaura ◽  
Muneyasu Suzuki ◽  
Hiroshi Uchida ◽  
Seiichiro Koda
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Temperature Coefficient ◽  
Annealing Temperature ◽  
Relative Dielectric Constant ◽  
Fused Silica ◽  
The Other ◽  
Other Hand ◽  
Silica Substrates

Effect of annealing temperature on the dielectric properties of Bi1.5Zn1.0Nb1.5O7 films prepared on (111)Pt//(001)Al2O3 and (111)Pt/fused silica substrates by MOCVD was investigated. The tunability and the inverse of the dielectric loss [1/ (tan )] increased with increasing annealing temperature. Relative dielectric constant and temperature coefficient of the capacitance (TCC) increased with the crystallinity of the films. On the other hand, (1/tan ) was independent of the crystallinity of the films, but was dramatically increased by the annealing.

scholarly journals The contribution of 180° domain wall motion to dielectric properties quantified from in situ X-ray diffraction

2017 ◽  
Vol 126 ◽  
pp. 36-43 ◽  
Author(s):  
C.M. Fancher ◽  
S. Brewer ◽  
C.C. Chung ◽  
S. Röhrig ◽  
T. Rojac ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Domain Wall ◽  
Wall Motion ◽  
Domain Wall Motion ◽  
X Ray Diffraction ◽  
X Ray

Dielectric Properties and Leakage Current Characteristics of Al2O3 Thin Films with Thickness Variation

2001 ◽  
Vol 666 ◽  
Author(s):  
Jae-Hoon Choi ◽  
Ji-Woong Kim ◽  
Tae-Sung Oh
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Film Thickness ◽  
Leakage Current ◽  
Thickness Variation ◽  
Tangent Loss ◽  
Maximum Dielectric Constant ◽  
Current Densities ◽  
Current Characteristics

ABSTRACTDielectric properties and leakage current characteristics of the Al2O3 thin films, deposited by reactive sputtering at room temperature, have been investigated with variations of the O2 content in the sputtering gas and the film thickness. The Al2O3 films of 10-300 nm thickness were amorphous without depending on the O2 contents of 25-75% in the sputtering gas. Maximum dielectric constant was obtained for the Al2O3 film deposited with the sputtering gas of 50% O2 content. With reduction of the film thickness from 300 nm to 10 nm, dielectric constant decreased from 9.04 to 3.71 and tangent loss increased from 0.0035 to 0.0594, respectively. When the O2 content in the sputtering gas was higher than 50%, the Al2O3 films exhibited no shift of the flatband voltage in C-V curves. The leakage current density increased with increasing the film thickness, and the Al2O3 films thinner than 100 nm exhibited the leakage current densities lower than 10−6 A/cm up to 650 kV/cm.

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