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.

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.

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

Structural analysis of lead magnesium niobate using synchrotron powder X-ray diffraction and the Rietveld method

2016 ◽  
Vol 72 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Ashok Bhakar ◽  
Adityanarayan H. Pandey ◽  
M. N. Singh ◽  
Anuj Upadhyay ◽  
A. K. Sinha ◽  
...  
Keyword(s):  
Cell Volume ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Rietveld Method ◽  
Unit Cell ◽  
Lead Magnesium Niobate ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Magnesium

The room-temperature synchrotron powder X-ray diffraction pattern of the single phase perovskite lead magnesium niobate (PMN) has shown significant broadening in theqrange ∼ 5–7 Å−1compared with standard LaB6synchrotron powder X-ray diffraction data, taken under similar conditions. This broadening/asymmetry lies mainly towards the lower 2θ side of the Bragg peaks. Attempts to fit this data with the paraelectric cubic phase (Pm\bar 3m) and the local rhombohedral phase (R3m) corresponding to polar nanoregions (PNRs) are made using the Rietveld method. Rietveld refinements show that neither cubic (Pm\bar 3m) nor rhombohedral (R3m) symmetry can fit this XRD pattern satisfactorily. The two-phase refinement fits the experimental data satisfactorily and suggests that the weight percentage of the PNRs is approximately 12–16% at room temperature. The unit-cell volume of these rhombohedral PNRs is approximately 0.15% larger than that of the unit cell volume of the paraelectric cubic phase.

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.

Single crystal x-ray diffraction of lead magnesium niobate-lead titanate in the transmission mode

2006 ◽  
Vol 89 (9) ◽  
pp. 092903 ◽  
Author(s):  
Alp Sehirlioglu ◽  
David A. Payne ◽  
Scott R. Wilson ◽  
Pengdi Han
Keyword(s):  
Single Crystal ◽  
Lead Titanate ◽  
Lead Magnesium Niobate ◽  
Transmission Mode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Niobate ◽  
Lead Magnesium

Preparation and Characterization of γ-Fe2O3-ZnFe2O4 Composite Nanoparticles

2013 ◽  
Vol 873 ◽  
pp. 152-157
Author(s):  
Long Long Chen ◽  
Jun Ming Li ◽  
Xiao Min Gong ◽  
Jian Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Species ◽  
Composite Nanoparticles ◽  
X Ray Diffraction ◽  
Ferrite Core ◽  
Phase Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Chemically Induced

Using a chemically induced transition in an FeCl2 solution, γ-Fe2O3 nanoparticles can be prepared from an amorphous precursor composed of FeOOH and Mg (OH)2. Surface modification by adding ZnCl2 during liquid-phase synthesis was attempted. The magnetization, morphology, crystal structure, and chemical species of as-prepared samples were characterized by vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy-dispersive spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the surface of the γ-Fe2O3 nanoparticles can be modified by adding ZnCl2 to form composite nanoparticles with a γ-Fe2O3/ZnFe2O4 ferrite core coated with Zn (OH)2 and absorbed FeCl36H2O; this modification can be enhanced by additional NaOH.

Rapid Synthesis and Characterization of CuInS2 Prepared Using Microwave-Assisted Heating

2015 ◽  
Vol 775 ◽  
pp. 143-146
Author(s):  
Ming Kwen Tsai ◽  
Yueh Chien Lee ◽  
Chia Chih Huang ◽  
Sheng Yao Hu ◽  
Kwong Kau Tiong ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Rapid Synthesis ◽  
X Ray ◽  
Sem Image ◽  
Microwave Assisted ◽  
Calcination Treatment ◽  
Scanning Electron

In this work, the CuInS2 nanoparticles are successfully synthesized by microwave-assisted heating technique and further calcined at 400 °C. The morphological, structural, and optical properties of the synthesized CuInS2 nanoparticles are investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Raman scattering, and transmittance measurement, respectively. The SEM image shows the clear particle shape of the calcined CuInS2 nanoparticles. After calcination treatment, the fundamental (112) peak of the XRD spectrum and a broad Raman peak mixed with chalcopyrite and CuAu structures support the improved crystallinity of the calcined CuInS2 nanoparticles.

Characterization and genesis of horizontal banding in Brazilian agate: an X-ray diffraction, thermogravimetric and electron microprobe study

2013 ◽  
Vol 77 (3) ◽  
pp. 227-248 ◽  
Author(s):  
T. Moxon ◽  
C. M. Petrone ◽  
S. J. B. Reed
Keyword(s):  
Amorphous Silica ◽  
Electron Microprobe ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wall Lining ◽  
Defect Site ◽  
Site Water ◽  
Stage Process ◽  
Upper Chamber

AbstractCharacterization of Brazilian agates containing a lower horizontally banded section and an upper chamber with bands parallel to the walls shows that these agates formed much later than the 135 Ma Paraná basalt host rock. Age differentiation between the two types of banding shows that the horizontal bands formed between 43 to 63 Ma ago with a final infill of wall-lining bands between 7 and 27 Ma later. The horizontal bands have a higher Al3+ concentration and a greater crystallite size than the wall-lining layers; they have a lower mogánite content and defect-site water content. The formation of these agates appears to be the result of a three-stage process. After the separate formation of horizontally banded and wall-lining agate, a silica infill seals the gap between the agate and the cavity wall. The detection of cristobalite in some specimens indicates that genesis of both the horizontally banded and wall-lining deposits in the Brazilian samples proceeds along an amorphous silica → opal-CT → opal-C → chalcedony pathway.

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