STRUCTURE-PROPERTIES RELATION OF CO-DOPE BISMUTH LAYER-STRUCTURED Bi3.25La0.75(Ti1-xWx)3O12 CERAMICS

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3793-3799
Author(s):  
PASINEE SIRIPRAPA ◽  
ANUCHA WATCHARAPASORN ◽  
SUKANDA JIANSIRISOMBOON
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Lattice Distortion ◽  
Ferroelectric Properties ◽  
Doping Content ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Structure Properties

In this work, fabrication and investigation of substituing high-valence W 6+ for Ti 4+ ion on B -site of La 3+-doped Bi 4 Ti 3 O 12 or BLT structure to form Bi 3.25 La 0.75( Ti 1-x W x)3 O 12 or BLTW (when x = 0, 0.01, 0.03, 0.05 0.07, 0.09 and 0.10) ceramics were carried out. X-ray diffraction patterns of BLTW ceramics indicated orthorhombic structure with lattice distortion, especially with higher concentration of WO 3 dopant. An increase in WO 3 doping content reduced not only length and thickness of grain, but also density of the ceramics. Electrical conductivity was found to decrease, while dielectric constant increased with W 6+ doping. Ferroelectric properties were found to be improved with increasing WO 3 content and were optimized at x = 0.05.

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.

scholarly journals Structural and Dielectric Properties of (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) Nanocomposites

2021 ◽  
Author(s):  
A. Mallikarjuna ◽  
N. Suresh Kumar ◽  
T. Anil Babu ◽  
S. Ramesh ◽  
Chandra Babu Naidu K
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
Dielectric Behavior ◽  
Perfect Absorber ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Diffraction Patterns

Abstract (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) [ALTBZFO] nanocomposites were synthesized via hydrothermal method. The X-ray diffraction patterns indicated the phase transformation from tetragonal to cubic for x = 0.2 to 0.4 - 0.8 samples, respectively. The surface morphology showed the existence of nanospheres like structures. At 1 MHz frequency also, the dielectric constant was increased from 230 to 710 for x = 0.2 – 0.6 samples, respectively. But, interestingly, x = 0.6 nanocomposite exhibited the negative dielectric behavior having the dielectric constant (ε') ~ -58.5 and dielectric loss (ε") ~ -417 at 8 MHz. Likewise, x = 0.6 sample showed ac-electrical conductivity (σac) -0.159 S/cm at 6 MHz. Hence, these kinds of materials can provide high charge stored capacitor, and perfect absorber applications.

The Influences of NaNbO3 on the Dielectric and Structure Characteristics of (1-X) (Na0.5Bi0.5)TiO3–x NaNbO3 Ceramics

2011 ◽  
Vol 415-417 ◽  
pp. 1064-1069 ◽  
Author(s):  
Chia Ching Wu ◽  
Ying Hsun Lin ◽  
Ping Shou Cheng ◽  
Chao Chin Chan ◽  
Cheng Fu Yang
Keyword(s):  
Dielectric Constant ◽  
Ferroelectric Properties ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Depolarization Temperature ◽  
Dielectric Characteristics ◽  
X Ray ◽  
Maximum Dielectric Constant ◽  
Second Phases ◽  
Xrd Patterns

Perovskite-based (1-x) (Na0.5Bi0.5)TiO3-x NaNbO3 [(1-x) NBT-x NN, x = 0.1, 0.2, 0.3 and 0.4] ceramics were sintered at 1080°C. Dielectric characteristics, crystalline structures, and Raman investigations were carried out on (1-x) (Na0.5Bi0.5)TiO3-x NaNbO3 ceramics. X-ray diffraction (XRD) patterns showed that NaNbO3 ceramic would form a solid solution with (Na0.5Bi0.5)TiO3 ceramic, and and unknown or second phases were not observable as well. NaNbO3 ceramic diffused into the crystalline structure of (Na0.5Bi0.5)TiO3 ceramic and (1-x) NBT-x NN ceramics still revealed a rhombohedral structure. The temperature-dielectric constant curves showed that as NN content increased, the temperature to reveal the maximum dielectric constant (Tm) was raised, the depolarization temperature (Td) was shifted to lower value, and the dielectric constant at Tm and the loss tangent at Td gradually decreased. The Raman bands at 770 and 830 cm-1 were attributed to the existence of the oxygen vacancies. In this study, the relaxor-type ferroelectric properties of NBT ceramic had been improved as NN ceramic was added.

scholarly journals Influence of Processing Conditions on Crystal Structure of Bi6Fe2Ti3O18 Ceramics

2016 ◽  
Vol 61 (2) ◽  
pp. 881-886 ◽  
Author(s):  
A. Lisińska-Czekaj ◽  
M. Lubina ◽  
D. Czekaj ◽  
M. Rerak ◽  
B. Garbarz-Glos ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ambient Air ◽  
Processing Conditions ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Number Of Layers ◽  
Solid State Reaction Route ◽  
Diffraction Patterns

Abstract Aim of the present research was to apply a solid state reaction route to fabricate Aurivillius-type ceramics described with the formula Bi6Fe2Ti3O18 (BFTO) and reveal the influence of processing conditions on its crystal structure. Pressureless sintering in ambient air was employed and the sintering temperatures were 850 and 1080 °C. It was found that the fabricated BFTO ceramics were multiphase ones. They consisted of two Bim+1Fem-3Ti3O3m+3 phases, namely the phase with m=5 (i.e. the stoichiometric phase) and m=4 (i.e. the phase with a reduced number of layers in the slab). Detailed X-ray diffraction patterns analysis showed that both phases adopted the same orthorhombic structure described with Fmm2 (42) space group. The ratio of weight fractions of the constituent phases (m=5): (m=4) was ~30:70.

scholarly journals Electrical Conductivity and Chemical Equilibria of Coordination Biopolymeric Cerium (IV)-Alginate Complex with Correlation between the Structure and Complex Stability

2015 ◽  
Vol 7 (2) ◽  
pp. 57 ◽  
Author(s):  
Ishaq Zaafarany ◽  
Hatem Altass ◽  
Jabir Alfahemi ◽  
Khalid Khairou ◽  
Refat Hassan
Keyword(s):  
Electrical Conductivity ◽  
Conduction Mechanism ◽  
Research Study ◽  
Coordination Geometry ◽  
Complex Stability ◽  
X Ray Diffraction ◽  
Chemical Equilibria ◽  
X Ray ◽  
Infrared Absorption Spectra ◽  
Diffraction Patterns

In this research study, the cross-linked cerium (IV)-alginate complex, as coordination biopolymeric compound in the granules form, was prepared. It has been indicated from the x-ray diffraction patterns that the nature of alginate complex is amorphous. Additionally, it has been revealed from the infrared absorption spectra that cerium (IV) chelates the alginate macromolecular chains in the complex. The study has displayed that the range of us OCO- is 1424 cm-1and the range of uasOCO- is 1605 cm-1. This indicates that a complexation type between the cation Ce4+ and both carboxylate and hydroxyl functional groups of alginate macromolecule is usually takes place. The study has also measured the electrical conductivity (s) of coordination biopolymeric cerium (IV)-alginate complex, as function of temperature. It has been indicated from the measured value of the electrical conductivity, i.e., 1.04 x10-9 Siemens at 20oC that the conductance of the complex lies in the range of semiconductors. The research has profoundly discussed with evaluation of the thermodynamic parameters. Afterwards, appropriate conduction mechanism based on the electrical conductivity and chemical equilibrium has also been suggested and discussed in terms of the complex stability in correlation with its coordination geometry.

Electrical Properties of Modified BNT Based Lead-Free Ceramics

2016 ◽  
Vol 872 ◽  
pp. 87-91
Author(s):  
Supalak Manotham ◽  
Tawee Tunkasiri ◽  
Pharatree Jaita ◽  
Pichitchai Butnoi ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Free Ceramics

The properties of modified Bi0.5Na0.5TiO3 (BNT) based lead-free ceramics were investigated. The BNT-based ceramics were prepared by a solid-state mixed oxide method Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggested that all samples exhibited a perovskite structure without second phase. The value of dielectric constant increased with increasing in sintering temperature. Moreover, high sintering temperatures could improve ferroelectric properties of BNT base lead-free ceramics.

Sinterbility of (Bi4-xLax)Ti3O12 Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 841-844 ◽  
Author(s):  
Pasinee Siriprapa ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Grain Orientation ◽  
Sintering Temperature ◽  
Orthorhombic Phase ◽  
Preferred Orientation ◽  
Doping Content ◽  
X Ray Diffraction ◽  
Microstructural Investigation ◽  
X Ray ◽  
Lanthanum Titanate ◽  
Diffraction Patterns

This research studied the effects of sintering temperature and La3+ doping content on phase, microstructure and densification of bismuth lanthanum titanate (Bi4-xLaxTi3O12; BLT) ceramics when x = 0, 0.25, 0.5, 0.75 and 1.0, respectively. The BLT powders were prepared using a mixed-oxide method. The mixtures were calcined at 750°C for 4 h before being pressed and sintered at 1000-1150°C for 4 h. The result of phase analysis by X–ray diffraction (XRD) indicated the existence of orthorhombic phase for all sintering temperatures. The XRD peak intensities of the ceramics showed preferred orientation of a particular set of {00l}-type planes. The ceramics mainly composed of plate-like grains. Increasing the sintering temperature increased grain size and increased preferred grain orientation. The present of La3+ in BLT ceramics reduced preferred orientation especially at higher sintering temperature. Results of microstructural investigation agreed well with X-ray diffraction patterns.

scholarly journals Analysis of X-ray structure, dielectric properties and AC conductivity of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one

2016 ◽  
Vol 34 (2) ◽  
pp. 386-392 ◽  
Author(s):  
H.A.M. Ali ◽  
Magdy A. Ibrahim
Keyword(s):  
Crystal Structure ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Relaxation Time ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Different Temperatures

AbstractThe crystal structure of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one, denoted as 4(E)-ACBO, was analyzed using X-ray diffraction technique. The dielectric and AC electrical conductivity measurements of the bulk 4(E)-ACBO in the form of pellet were studied in the range of frequency 42 Hz to 5 MHz and the temperature range of 303 K to 373 K. The temperature and frequency dependence of dielectric constant (∊1), dielectric loss (∊2) and AC electrical conductivity (σAC) were investigated. The relaxation time (τ) for electrons to hop over a barrier of height WH was calculated at different temperatures. The AC activation energy was determined from the temperature dependence of σAC at different frequencies.

Effect of CuO-TiO2 Eutectic on Thermal and Electrical Conductivities of CaCu3Ti4O12 Ceramics

2016 ◽  
Vol 881 ◽  
pp. 117-122
Author(s):  
Flavia dos Reis Gonçalves ◽  
Daniel Thomazini ◽  
Maria Virginia Gelfuso
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Laser Flash ◽  
Eutectic Phase ◽  
Flash Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical Conductivities ◽  
Diffraction Patterns

In this work, CaCuxTiyO12 ceramics (2.7 ≤ x ≤ 3.3 and 3.25 ≤ y ≤ 4.75), related to excess and deficiency of CuO-TiO2 eutectic phase have been synthesized by coprecipitation method. The crystalline phases in the ceramics were identified by X-ray diffraction patterns, and the pellets have mainly presented CCTO and also exhibited CuO, TiO2 and CaTiO3 as secondary phases. The thermal conductivity of the ceramics was determined using the laser flash method in the temperature range of 300-1000 K. It was observed a decrement in thermal conductivity values as the amount of the eutectic phase decreased. The electrical DC conductivity has been measured by the two-probe method from 300-1000 K and it has been noted that both grain size and amount of eutectic phase influenced the electrical conductivity results.

The Influence and Mechanism of the Electrical Conductivity of (Ca,Sr)Bi4Ti4O15 Piezoelectric Ceramics by Doping of CeO2

2007 ◽  
Vol 280-283 ◽  
pp. 263-266 ◽  
Author(s):  
Liao Ying Zheng ◽  
Guo Rong Li ◽  
Wang Zhong Zhang ◽  
Qing Rui Yin
Keyword(s):  
Layered Structure ◽  
Oxygen Vacancies ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Doping Content ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Perovskite Layer ◽  
Reaction Method ◽  
X Ray

In this paper, the bismuth-layered structure piezoelectric ceramics (Ca,Sr)Bi4Ti4O15 doped with CeO2 are prepared by the solid state reaction method. The crystal structure of the ceramics is determined by X-ray diffraction and the single orthorhombic structure phase is found. However, the doping of CeO2 increase the lattice parameters a, b, c. As a result, the ions of Ce enter into the lattice of the bismuth-layered structure and occupy A sites in the perovskite layer of bismuthlayered structure lattice. The temperature dependence of the conductivity shows that the resistivity increases by doping of CeO2 and reaches its maximum when the doping content is 0.4mol%. The mechanism of the CeO2 doping is also analyzed. By the investigation of XPS, the Ce ions have two types of valences: Ce3+ and Ce4+. The existence of Ce ions strengthened the weak Bi-O bonding and decreased the oxygen vacancies in the lattice, so the ceramics have lower conductivity.

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