Relaxor Ferroelectricity and Electrostrictive Behavior of KNN-ST Ceramics

2010 ◽  
Vol 654-656 ◽  
pp. 1978-1981
Author(s):  
Hui Qing Fan ◽  
Zhuo Li ◽  
Peng Rong Ren ◽  
Gang Cheng Jiao
Keyword(s):  
Electric Fields ◽  
High Dielectric Constant ◽  
Narrow Range ◽  
Ferroelectric Properties ◽  
Lead Magnesium Niobate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Magnesium ◽  
Diffraction Patterns ◽  
High Dielectric

The new electrostrictive ceramics have been produced from the (1-x) K0.5Na0.5NbO3-xSrTiO3 (KNN-ST, x=0.1-0.25) system by using conventional mixed-oxide methods. Sintering temperatures rise with increasing SrTiO3 content (x=0.1-0.25) and are in a very narrow range. The x-ray diffraction patterns indicate that with the increasing of SrTiO3 up to 0.25, KNN-ST ceramics with a single perovskite structure exhibit a transition from orthorhombic to cubic and no other impure phase appeared. The dielectric and relaxor ferroelectric properties of KNN-ST ceramics are investigated with the different SrTiO3 content. Also, the strain of these ceramics induced by applied electric fields have been studied. The electrostrictive response is similarly as in the classical PMN (lead magnesium niobate), but lower (order of the 10-5) than PMN (order of the 10-3). Furthermore, this system shows translucent, high dielectric constant, thus suggests possible applications in electric-optic devices, electromechanical transducer applications.

Fabrication and Characterization of Metal-Ferroelectric-Gan Structures

1999 ◽  
Vol 595 ◽  
Author(s):  
W.P. Li ◽  
R. Zhang ◽  
J. Yin ◽  
X.H. Liu ◽  
Y.G. Zhou ◽  
...  
Keyword(s):  
High Frequency ◽  
High Dielectric Constant ◽  
Oxide Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Active Layers ◽  
Pzt Films ◽  
High Dielectric ◽  
Mos Structures

AbstractGaN-based metal-ferroelectric-semiconductor (MFS) structure has been fabricated by using ferroelectric Pb(Zr0.53Ti0.47)O3 (PZT) instead of conventional oxides as gate insulators. The GaN and PZT films in the MFS structures have been characterized by various methods such as photoluminescence (PL), wide-angle X-ray diffraction (XRD) and high-resolution X-ray diffraction (HRXRD). The Electric properties of GaN MFS structure with different oxide thickness have been characterized by high-frequency C-V measurement. When the PZT films are as thick as 1 µm, the GaN active layers can approach inversion under the bias of 15V, which can not be observed in the traditional GaN MOS structures. When the PZT films are about 100 nm, the MFS structures can approach inversion just under 5V. All the marked improvements of C-V behaviors in GaN MFS structures are mainly attributed to the high dielectric constant and large polarization of the ferroelectric gate oxide.

Preparation and Characterization of Relaxor-Based Ferroelectric Thick Films with Single Perovskite Structure

2008 ◽  
Vol 368-372 ◽  
pp. 24-26 ◽  
Author(s):  
Hui Qing Fan ◽  
Jin Chen ◽  
Xiu Li Chen
Keyword(s):  
Deposition Time ◽  
Thick Films ◽  
Colloidal Suspensions ◽  
Lead Magnesium Niobate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Films ◽  
Deposition Voltage ◽  
Lead Magnesium

Lead magnesium niobate-lead titanate (0.8Pb(Mg1/3Nb2/3)O3-0.2PbTiO3, PMN-PT) thick films in the thickness range about 75 μm have been successfully fabricated on Au-coated Al2O3 substrates by electrophoretic deposition (EPD). Non-aqueous colloidal suspensions suitable for EPD were prepared by mixing ultrasonically PMN-PT particles in ethanol with pH=6.0. The effect of EPD process parameters such as deposition voltage, deposition time and the specific deposition mass of PMN-PT particles were investigated. The EPD parameters were optimized in order to obtain crack-free, high-quality uniform ceramic films. The deposited pyrochlore-free PMN-PT thick films were sintered at 1000oC for 30 min, and the phase evolvement and the microstructure of the film were characterized by X-ray diffraction and scanning electron microscope.

Study of Microstructure in 0.9PMNTa-0.1PT Ceramics

2000 ◽  
Author(s):  
Jin T. Wang ◽  
Feng Tang
Keyword(s):  
Grain Size ◽  
Lead Titanate ◽  
Lead Magnesium Niobate ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Content ◽  
Lead Magnesium ◽  
Ta Doping ◽  
Scanning Electron

Abstract Ta-Doping effect on the microstructure of lead magnesium niobate-lead titanate crystalline solutions 0.9PbMg1/3(Nb(1−x)Tax)2/3O3-0.1PbTiO3(PMN-PT) have been firstly investigated in this paper. Scanning Electron Micrographs (SEM) were taken from fractured surfaces of the samples with different additives of x = 0.0, 0.1, 0.2, 0.3 and 1.0 by Hitachi F-2460N microscope operating at an accelerating voltage of 25kV. The chemical content analysis for the synthesized samples performed on JEOL Super Prob733 Energy Perspective Spectrum. The x-ray diffraction was carried out with a Siemens D5000 Dual Diffraction Meter. It is clearly evident that doping Ta in PMNTa-PT can affect the grain size and density of the compounds. Smaller grain size (3.1μm) is formed in the specimens with the additives of x = 0.1, 0.2 and 0.3 in comparison with those of the specimens without doping (6.6μm) or over doping (6.4μm). The porosity at grain intersections increase with increasing of additive tantalum for niobium site in 0.9PMNTa-0.1PT. Larger grain size (6.4μm), greater non-uniformity and more inter-granular voids are found in the compound, if tantalum completely substitutes niobium (x = 1). No non-reacted starting regents were observed in any of the compositions mentioned above.

Effects of Donor Doping on Microstructure and Electrical Properties of Bismuth Layer-Structured Bi4Ti3O12 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 259-262 ◽  
Author(s):  
Lina Zhang ◽  
Su Chuan Zhao ◽  
Liao Ying Zheng ◽  
Guo Rong Li ◽  
Qing Rui Yin
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
Suitable Candidate ◽  
X Ray ◽  
Donor Doping ◽  
Diffraction Patterns

A study was conducted on the effects of donor dopants, Nb2O5 and WO3, on microstructure and electric properties of Bi4Ti3O12 (BIT) ceramics. X-ray diffraction patterns of the materials showed a single orthorhombic phase structure. The microstructure results revealed the appearance of plate-like grain. The donor doping decreased the conductivity of BIT by as much as 3 orders of magnitude. The dielectric and ferroelectric properties of doped-BIT materials were also investigated. The decrease in the electrical conductivity allowed the doped samples to be poled to develop piezoelectricity. Thermal annealing studies of the samples indicated the donor-doped BIT were suitable candidate materials for high-temperature piezoelectric applications.

The Synthesis and Characterization of SrTiO3 Film Fabricated by Micro Arcoxidation

2011 ◽  
Vol 311-313 ◽  
pp. 1262-1266 ◽  
Author(s):  
Hui Yong Guo ◽  
Wen Bo Huang ◽  
Wen Fang Li ◽  
Guo Ge Zhang ◽  
En Fu Wang
Keyword(s):  
Surface Morphology ◽  
High Dielectric Constant ◽  
Electrolyte Concentration ◽  
Pure Titanium ◽  
Xrd Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Dielectric

Pure titanium plates as anode and mixture of solutions containing 0.2M Sr(OH)2and 0.2M NaOH as electrolyte, titanium plates were microarc-oxidated for 10 minutes. X-Ray Diffraction (XRD) analysis indicated that SrTiO3film was successfully deposited. The MAO film is composed mainly of tetragonal SrTiO3phases and found to possess high dielectric constant of 371.0 at the frequency of 1 kHz. Scanning Electron Microscopy (SEM) and portable roughness tester were used to characterize the surface morphology and roughness values(Ra), The influences of electrolyte concentration, current density and frequency on the surface morphology of SrTiO3film were investigated in detail . several rules were drawn from the results. A kinetics expression was established for the growth of film thickness and agreed well with the experimental results.

Surface Characterisation of the Corundum-Route Lead Magnesium Niobate Ferroelectric Ceramics

2011 ◽  
Vol 194-196 ◽  
pp. 2046-2049
Author(s):  
Laongnuan Srisombat ◽  
Rewadee Wongmaneerung ◽  
Rattikorn Yimnirun ◽  
Supon Ananta
Keyword(s):  
Chemical Species ◽  
Lead Magnesium Niobate ◽  
Ferroelectric Ceramics ◽  
X Ray Diffraction ◽  
Surface Characterisation ◽  
X Ray ◽  
Sem Image ◽  
Microscopy Technique ◽  
Lead Magnesium ◽  
Stage Process

Perovskite relaxor ferroelectric PMN ceramics, Pb (Mg1/3Nb2/3O3), have been fabricated using a two-stage process employing a corundum-type Mg4Nb2O9 as a key precursor. The 100% perovskite PMN ceramics was revealed by X-ray diffraction analysis. The SEM image of the PMN ceramic shows irregular shape PMN grains on the porous surface. The surface chemical composition of the PMN ceramics could be characterized by X-ray photoelectron microscopy technique. The XPS results indicate most of the elements consist of more than one chemical species. The important of XPS studies here can reveal small amount of species which could not detected by XRD.

An X-ray diffraction study of superlattice ordering in lead magnesium niobate

1996 ◽  
Vol 97 (8) ◽  
pp. 693-698 ◽  
Author(s):  
Q.M Zhang ◽  
Hoydoo You ◽  
Maureen L Mulvihill ◽  
S.J Jang
Keyword(s):  
Diffraction Study ◽  
Lead Magnesium Niobate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Niobate ◽  
Lead Magnesium

Effect of Pb Volatilization on Dielectric Properties of 0.77PbMg1/3(Nb0.9Ta0.1)2/3O3-0.23PbTiO3

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3738-3744 ◽  
Author(s):  
C. Zhang ◽  
J. T. Wang ◽  
M. Q. Qian ◽  
T. P. Chen ◽  
I. Akujobi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Lead Magnesium Niobate ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
Dielectric Constant And Loss ◽  
Different Temperatures ◽  
Lead Magnesium ◽  
High Dielectric ◽  
The Cost

Lead magnesium niobate-lead titanate (PMN-PT) is an intriguing candidate for applications in many electronic devices such as multi-layer capacitors, electro-mechanical transducers etc. because of its high dielectric constant, low dielectric loss and high strain near the Curie temperature. As an extension of our previous work on Ta-doped PMNT-PT aimed at optimizing the performance and reducing the cost, this paper focuses on the effect of Pb volatilization on the dielectric properties of 0.77 Pb ( Mg 1/3( Nb 0.9 Ta 0.1)2/3) O 3-0.23 PbTiO 3. The dielectric constant and loss of the samples are measured at different frequencies and different temperatures. The phase purity of this compound is determined by X-ray diffraction pattern. It is found that the volatilization during sintering does influence the phase formation and dielectric properties. The best condition is sintering with 0.5 g extra PbO around a 4 g PMNT-PT sample.

scholarly journals Fabrication and Characterization of Metalferroelectric-GAN Structures

2000 ◽  
Vol 5 (S1) ◽  
pp. 598-604
Author(s):  
W.P. Li ◽  
R. Zhang ◽  
J. Yin ◽  
X.H. Liu ◽  
Y.G. Zhou ◽  
...  
Keyword(s):  
High Frequency ◽  
High Dielectric Constant ◽  
Oxide Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Active Layers ◽  
Pzt Films ◽  
High Dielectric ◽  
Mos Structures

GaN-based metal-ferroelectric-semiconductor (MFS) structure has been fabricated by using ferroelectric Pb(Zr0.53Ti0.47)O3 (PZT) instead of conventional oxides as gate insulators. The GaN and PZT films in the MFS structures have been characterized by various methods such as photoluminescence (PL), wide-angle X-ray diffraction (XRD) and high-resolution X-ray diffraction (HRXRD). The Electric properties of GaN MFS structure with different oxide thickness have been characterized by high-frequency C-V measurement. When the PZT films are as thick as 1 μm, the GaN active layers can approach inversion under the bias of 15V, which can not be observed in the traditional GaN MOS structures. When the PZT films are about 100 nm, the MFS structures can approach inversion just under 5V. All the marked improvements of C-V behaviors in GaN MFS structures are mainly attributed to the high dielectric constant and large polarization of the ferroelectric gate oxide.

Sign in / Sign up

Export Citation Format

Share Document