Phase Formation and Microstructure of PBZT Powders Prepared via Mixed Oxide Method

2008 ◽  
Vol 55-57 ◽  
pp. 201-204 ◽  
Author(s):  
Theerachai Bongkarn ◽  
C. Thiangchit
Keyword(s):  
Phase Formation ◽  
Mixed Oxide ◽  
Structural Phase ◽  
Orthorhombic Phase ◽  
Barium Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Zirconate Titanate ◽  
Dta Curves ◽  
Scanning Electron

In this study, lead barium zirconate titanate [(Pb0.975Ba0.025)(Zr1-xTix); (PBZT)] powders with 0 £ x £1 were prepared via the mixed oxide method. The calcinations were performed between 800 and 1000 oC for 1 h. The phase formation and microstructure was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the structural phase indexed in the orthorhombic phase for x = 0. The tetragonal phase was detected in 0.25 £ x £ 1 samples. TG and DTA curves corresponded to XRD results. The SEM result indicated that the particle size of the powders were nonconsistant and ranged from ~0.5 to ~1.3 µm.

Effects of Manganese Addition on Phase Formation Behavior and Dielectric Properties of ((K0.5Na0.5)0.935Li0.065)NbO3 Ceramics

2014 ◽  
Vol 608 ◽  
pp. 206-211
Author(s):  
Supattra Wongsaenmai ◽  
Santi Maensiri ◽  
Rattikorn Yimnirun
Keyword(s):  
Dielectric Properties ◽  
Phase Formation ◽  
Single Phase ◽  
Structural Phase ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Formation Behavior ◽  
Different Grain Size ◽  
Scanning Electron

In this study, ceramics in ((K0.5Na0.5)0.935Li0.065)NbO3+ xMnO2(mol%) ceramics (when x = 0.0025, 0.0050, 0.01 and 0.015) were successfully prepared by the conventional mixed-oxide technique. The structural phase formation and microstructure were characterized by x-ray diffraction technique (XRD) and scanning electron microscopy (SEM). The crystal structure was identified by XRD as a single-phase perovskite structure, with tetragonal symmetry. The microstructure shows different grain size with different composition x. This study clearly showed that the Mn has influence on the dielectric properties in ((K0.5Na0.5)0.935Li0.065)NbO3ceramics.

Preparation and Properties of B2O3-Doped Ba(Zr0.07Ti0.93)O3 Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 149-152 ◽  
Author(s):  
P. Jarupoom ◽  
Gobwute Rujijanagul ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri
Keyword(s):  
Electron Microscopy ◽  
Sintering Temperature ◽  
Sintered Sample ◽  
Ferroelectric Ceramics ◽  
Barium Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Zirconate Titanate ◽  
Property Measurement ◽  
Scanning Electron

In this work, barium zirconate titanate (Ba(Zr0.07Ti0.93)O3) ferroelectric ceramics doped with B2O3 were prepared by the conventional mixed-oxide method. The properties of the ceramics as a function of sintering temperature were investigated. Various technique such as X-ray diffraction (XRD) technique, scanning electron microscopy, dielectric permittivity spectroscopy and ferroelectric property measurement were used to obtain characteristic of the ceramics. The optimum density was observed for 1250 oC sintered sample. An increase in sintering temperature produced a decrease in dielectric constant. However, ferroelectric behavior was improved in 1275 oC sintered sample. The results were discussed in term of microstructure and crystallinity of the ceramics.

scholarly journals Structural and optical study of the phase transitions in Lead Hafnate, PbHfO3

2014 ◽  
Vol 70 (a1) ◽  
pp. C58-C58
Author(s):  
Steven Huband ◽  
Anthony Glazer ◽  
Krystian Roleder ◽  
Andrzej Majchrowski ◽  
Pam Thomas
Keyword(s):  
Phase Transitions ◽  
Structural Phase ◽  
Orthorhombic Phase ◽  
Temperature Hysteresis ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Fundamental Understanding ◽  
Distinct Temperature

Lead Hafnate undergoes two structural phase transitions as a function of temperature. The first occurs at about 1630C, consisting of a transition from an antiferroelectric orthorhombic Pbam structure [1] to another antiferroelectric orthorhombic phase with an as-yet undetermined space group. The second is to a paraelectric cubic Pm3m structure at 2090C. Dielectric spectroscopy measurements on a single crystal have shown a distinct temperature hysteresis at the orthorhombic to orthorhombic transition [2]. Recently, dielectric measurements on a ceramic sample have shown a much larger temperature hysteresis and following x-ray diffraction measurements, it is suggested that the second orthorhombic phase is in space group A2mm and undergoes another transition to a tetragonal P4mm structure before the cubic transition [3]. We report on the results of an investigation of a PbHfO3crystal using a combination of high-resolution x-ray diffraction and birefringence imaging measurements with the Metripol system. These measurements have been performed as a function of temperature from the room-temperature orthorhombic structure to the high-temperature cubic structure. The results are discussed both in the context of the published work and fundamental understanding of the origin of antiferroelectricity.

scholarly journals Preparation of BaZrO3 powders by a spray-drying process

2003 ◽  
Vol 18 (6) ◽  
pp. 1325-1332 ◽  
Author(s):  
B. Robertz ◽  
F. Boschini ◽  
A. Rulmont ◽  
R. Cloots ◽  
I. Vandriessche ◽  
...  
Keyword(s):  
Spray Drying ◽  
Precursor Solution ◽  
Barium Zirconate ◽  
Drying Process ◽  
X Ray Diffraction ◽  
High Quality ◽  
Corrosion Resistant ◽  
X Ray ◽  
Potential Use ◽  
Scanning Electron

The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with well-controlled composition and properties. However, the classical solid-state preparation of barium zirconate leads to an inhomogeneous powder unsuitable for applications in highly corrosive environment. For this paper, the possibility to use the spray-drying technique for the preparation of BaZrO3 powders with a controlled size distribution and morphology was investigated. The influence of the nature and concentration of the precursor solution and the influence of the spray-drying step are discussed on the basis of x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dilatometric measurements.

Fabrication of Lead Barium Titanate Ceramics via Conventional Solid-State Mixed Oxide Technique

2008 ◽  
Vol 55-57 ◽  
pp. 209-212 ◽  
Author(s):  
Theerachai Bongkarn ◽  
P. Panya
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mixed Oxide ◽  
Perovskite Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Grain Sizes ◽  
Titanate Ceramics ◽  
Scanning Electron

(Pb0.925Ba0.075)TiO3 (PBT) ceramics have been prepared using a mixed oxide technique. The phase formation and morphology were studied in detail via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The pure tetragonal perovskite structure was discovered with calcination temperatures above 800 oC. The percentage of perovskite phase and particle size tends to increase with the increasing of calcination temperatures. The PBT ceramics sintered at various temperatures belonged to a pure tetragonal perovskite phase. The average grain sizes increased from 0.90 to 6.44 µm with the increase of sintering temperatures from 1100 to 1200 oC. The highest density was obtained from the sample that sintered at 1150 and 1200 oC

Influence of Fabrication Processing on Perovskite Phase Formation of KNN-BZT

2008 ◽  
Vol 55-57 ◽  
pp. 113-116 ◽  
Author(s):  
M. Sutapun ◽  
R. Muanghlua ◽  
Chien Chih Huang ◽  
David P. Cann ◽  
Wanwilai C. Vittayakorn ◽  
...  
Keyword(s):  
Conventional Method ◽  
Mixed Oxide ◽  
Perovskite Phase ◽  
Complex Mixture ◽  
X Ray Diffraction ◽  
Two Stage ◽  
X Ray ◽  
Phase Development ◽  
Complete Solid Solution ◽  
Scanning Electron

The binary system of (1-x)(K1/2Na1/2)NbO3–xBi(Zn1/2Ti1/2)O3; x = 0.0-0.30 ceramics was fabricated by conventionally mixed oxide and two-stage mixed oxide methods. Phase development of calcined powders and the crystal structure of sintered ceramics were analyzed by X-ray diffraction (XRD). The microstructure analyses were undertaken by scanning electron microscopy (SEM). In the conventional method, the perovskite phases were obtained for compositions containing only 10 mol % KNN. For compositions above this amount, a complex mixture of phases was observed. However, the complete solid solution of perovskite phase, prepared by two−stage mixed oxide, was retained up to 20 mole % BZT content. The experiments in this study suggest that the two-stage mixed oxide method helps to stabilize the perovskite phase better, when compared with the conventional method.

scholarly journals Reheating of zinc-titanate sintered specimens

2015 ◽  
Vol 47 (1) ◽  
pp. 71-81
Author(s):  
N. Labus ◽  
S. Mentus ◽  
S. Rakic ◽  
Z.Z. Djuric ◽  
J. Vujancevic ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Zinc Titanate ◽  
X Ray ◽  
Microstructure Changes ◽  
Characteristic Temperatures ◽  
Air Atmosphere ◽  
Dta Curves ◽  
Scanning Electron

The scope of this work was observing dimensional and heat transfer changes in ZnTiO3 samples during heating in nitrogen and air atmosphere. Interactions of bulk specimens with gaseous surrounding induce microstructure changes during heating. Sintered ZnTiO3 nanopowder samples were submitted to subsequent heating. Dilatation curves and thermogravimetric with simultaneous differential thermal analysis TGA/DTA curves were recorded. Reheating was performed in air and nitrogen atmospheres. Reheated samples obtained at different characteristic temperatures in air were analyzed by X-ray diffraction (XRD). Microstructures obtained by scanning electron microscopy (SEM) of reheated sintered samples are presented and compared. Reheating in a different atmosphere induced different microstructures. The goal was indicating possible causes leading to the microstructure changes.

scholarly journals Synthesis and Characterizations of Doped Barium Zirconate – Alkali Carbonate Composite Electrolytes

2021 ◽  
Author(s):  
Gilles Taillades ◽  
Ismahan Hachemi ◽  
Mathieu Marrony ◽  
Julian Dailly
Keyword(s):  
Electron Microscopy ◽  
Charge Carriers ◽  
Interfacial Region ◽  
Barium Zirconate ◽  
Composite Electrolytes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Charge ◽  
Alkali Carbonate ◽  
Scanning Electron

Abstract Composite materials based on yttrium-doped zirconate (BaZr0.9Y0.1 O2.95, BZY) and eutectic compositions of alkali carbonates (Li2CO3, Na2CO3 and K2CO3) are investigated. These materials were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. This study evidences that the combination of BZY with carbonate promotes the densification and enhances the ionic conductivity which reaches 87 mS.cm-1 at 400°C for the BZY – LNK40 composite. In addition, the increase of the conductivity as a function of pH2 suggests that protons are the main charge carriers. The obtained results are interpreted by the transfer of protons from the ceramic to the carbonate phase in the interfacial region.

Room-temperature ferroelasticity and unusual sequence of phase transitions in the crystal of (N2H5)3[CdCl5]

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Monika K. Krawczyk ◽  
Zbigniew Czapla ◽  
Adam Ingram ◽  
Andrzej Kozdraś ◽  
Tadeusz Lis ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Room Temperature ◽  
Structural Changes ◽  
Structural Phase ◽  
Orthorhombic Phase ◽  
Orthorhombic Symmetry ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cl Atoms

On the basis of thermal analysis (DSC, DTA, DTG), single crystal X-ray diffraction experiments, dielectric studies and optical observation, it is found that the (N2H5)3[CdCl5] crystal exhibits several structural phase transitions. At room temperature, the studied crystal exhibits ferroelastic properties and undergoes phase transition from the monoclinic to the orthorhombic phase on heating above 327 K. Upon subsequent cooling, two structural phase transitions at about 323 and 319 K are observed, where the crystal adopts orthorhombic symmetry. The presented phase transitions are unique due to the fact the first heating run results in different structural changes compared to those observed during cooling and subsequent heating/cooling runs. In the studied crystal, N2H5 + ions and 1D chains built up from {CdCl5}3− units bridged by Cl atoms occur. The phase transitions observed can be associated with reorientation of cations and partial disorder of cations as well as Cl atoms.

Effect of Selenium on Structure and Electrical Property for Bi0.4Sb1.6Se3xTe3(1-x) Novel Hexagonal Rods

2013 ◽  
Vol 756 ◽  
pp. 80-84
Author(s):  
Arej Kadhim ◽  
Arshad Hmood ◽  
Abu Hassan Haslan
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Rhombohedral Phase ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Power Factor ◽  
Microscopy Images ◽  
Scanning Electron

Novel hexagonal rods of Bi0.4Sb1.6Se3xTe3(1-x) (0.0≤x≤1.0) were synthesized successfully through solid-state microwave synthesis. These hexagonal rods were explored using field emission scanning electron microscopy images. The X-ray diffraction results indicate that the powders (0.0≤x≤0.8) can be indexed as the rhombohedral phase, whereas the sample with x=1.0 has an orthorhombic phase structure. The electrical conductivity gradually decreases as Se increased, resulting in an increase in the Seebeck coefficient. Ascribing to the increased Seebeck coefficient for the sample with x=0.8, the maximum power factor is 7.47 mW/mK2 at 373 K.

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