scholarly journals Effect of synthesis route on the microstructure of SiO2 doped bismuth titanate ceramics

2009 ◽  
Vol 3 (4) ◽  
pp. 171-175 ◽  
Author(s):  
Elena Kashchieva ◽  
Milena Krapchanska ◽  
Stanislav Slavov ◽  
Yanko Dimitriev
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Bismuth Titanate ◽  
Batch Composition ◽  
Melt Quenching ◽  
Dense Microstructure ◽  
Binary Sample ◽  
Methods Of Synthesis ◽  
Quenching Method ◽  
Titanate Ceramics

Synthesis and characterization of SiO2 doped bismuth titanate ceramics were investigated. Four investigated compositions belonging to the system Bi2O3-TiO2-SiO2 are located in the section Bi4Ti3O12-SiO2, near by it and in the binary Bi2O3-TiO2 system. Melt quenching was applied for synthesis of SiO2 doped bismuth titanate ceramics and for the sample 40Bi2O3?60TiO2. The binary sample 70Bi2O3?30TiO2 is prepared by gradient heating of bulk materials near the liquidus temperature (modified solid state reaction). The influence of the thermal treatment on the phase formation and microstructure was evaluated using XRD, EDS and SEM. The binary samples prepared by solid state reaction at low temperature (1000?C) possess poly-phased dense microstructure, while secondary crystallization combined with porosity formation is typical for the sample obtained at high temperature (1150?C). The ternary Bi2O3-TiO2-SiO2 samples, obtained by supercooling of the melts down to room temperature, are thermally treated at 700, 800?C. They consist of elongated crystals in amorphous matrix. The crystals have lower Bi2O3-content and higher TiO2-content than the nominal batch composition. The XRD data show that the main crystalline phases in the ceramics produced by melt quenching method and solid state reaction are ?-Bi2O3, Bi4Ti3O12 and one unknown new phase. It is proved that the applied methods of synthesis are suitable for generation of different microstructures in the bulk SiO2 doped bismuth titanate ceramics, which is promising basis for modification of their electrical properties. .

scholarly journals Dielectric properties of bismuth titanate ceramics containing SiO2 and Nd2O3 as additives

2012 ◽  
Vol 6 (3) ◽  
pp. 117-122 ◽  
Author(s):  
Stanislav Slavov ◽  
Milena Krapchanska ◽  
Elena Kashchieva ◽  
Svetlin Parvanov ◽  
Yanko Dimitriev
Keyword(s):  
Room Temperature ◽  
Bismuth Titanate ◽  
Dielectric Materials ◽  
Dielectric Losses ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Quenching Method ◽  
Titanate Ceramics ◽  
Scanning Electron

Bismuth-titanate ceramics containing SiO2 and Nd2O3 as additives are synthesized by melt quenching method in the system Bi2O3-TiO2-Nd2O3-SiO2 in the temperature range of 1250-1500 ?C. The phase composition of the obtained materials is determined by X-ray diffraction analysis and energy dispersive spectroscopy. Using scanning electron microscopy different microstructures are observed in the samples depending on the composition. Different values of conductivity, dielectric losses and relative permittivity are obtained depending on the composition. It is established that all investigated samples are dielectric materials with conductivity between 10-9 and 10-13 (??cm)-1 at room temperature, dielectric permittivity from 1000 to 3000 and dielectric losses tg? between 0.0002 and 0.1.

scholarly journals Mechanical Behaviour and Fracture Mechanics of Praseodymium Modified Lead Titanate Ceramics Prepared by Solid-State Reaction Route

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Vishal Singh ◽  
Shivani Suri ◽  
K. K. Bamzai
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Lead Titanate ◽  
Applied Load ◽  
Hardness Testing ◽  
Solid State Reaction Technique ◽  
Reaction Route ◽  
Testing Method ◽  
Solid State Reaction Route ◽  
Titanate Ceramics

The praseodymium modified lead titanate ceramics with composition Pb1-xPrxTi0.96Fe0.02Mo0.02O3 where x = 0.04, 0.06, 0.08, and 0.10 prepared by solid-state reaction technique were subjected to indentation induced hardness testing method. The indentations were induced in the applied load ranging from 0.245 N to 4.90 N. The microhardness varies nonlinearly with load and was best explained by the concept of Newtonian resistance pressure as proposed by Hays and Kendall’s law. Crack propagation, fracture toughness (Kc), brittleness index (Bi), and yield strength (σy) were studied to understand the effect of Pr content on various mechanical parameters. The load independent values were found to increase with the increase in praseodymium content.

Ultrahigh Permittivity, Ultralow Loss and Stability in (In0.5Ta0.5)0.1Ti0.9O2 Ceramics With Temperature Range From -100 to 235 °C

2021 ◽  
Author(s):  
Ying Xue ◽  
Zhuo Wang ◽  
Yanxin Li ◽  
Zhihui Yi ◽  
Xin Li ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Dielectric Loss ◽  
Solid State Reaction ◽  
Electronic Devices ◽  
Dielectric Materials ◽  
Reducing Atmosphere ◽  
Dense Microstructure ◽  
Microelectronic Devices ◽  
Potential Applications

Abstract Dielectric materials with excellent dielectric properties are being promoted in requirements of microelectronic devices. In this study, (In0.5Ta0.5)0.1Ti0.9O2 ceramics were achieved by a solid-state reaction with reducing atmosphere of N2. Also, dense microstructure, ultrahigh permittivity (εr = 1.18 × 105) and ultralow dielectric loss (tanδ = 0.0072) were demonstrated at1 kHz. Interestingly enough, the temperature coefficient of permittivity which satisfies X9D (-100 °C - 235 °C, Δεr/ε25°C < ± 3.3 %) maintained stability at 1 kHz, and the dielectric mechanism could be connected to the electron-pinned defect dipoles (EPDD), which has favourable potential applications in electronic devices.

Raman Spectra of Bismuth Titanate Ceramics

2007 ◽  
Vol 555 ◽  
pp. 243-247 ◽  
Author(s):  
Z.Ž. Lazarević ◽  
N.Ž Romčević ◽  
M.J. Romčević ◽  
B.D. Stojanović
Keyword(s):  
Raman Spectroscopy ◽  
Solid State ◽  
Zirconium Oxide ◽  
Ball Mill ◽  
Bismuth Titanate ◽  
Ferroelectric Material ◽  
Spectroscopy Analysis ◽  
Conventional Solid State Reaction ◽  
Titanate Ceramics ◽  
Titanate Ceramic

Bismuth titanate is a typical layer-structured ferroelectric material and belongs to the Aurivilius type-structure compounds family. A bismuth titanate ceramic material could be obtained by mechanically activated synthesis after thermal treatment at a temperature slightly lower than in conventional solid-state reaction. In this case bismuth titanate was prepared through mechanochemical synthesis starting from bismuth oxide and titanium oxide in rutile form. The mixture of oxides was milled in a zirconium oxide jar in a planetary ball-mill in intervals from 1 to 12 hours. The ratio of powders to zirconium oxide balls during milling was 1:20. Bismuth titanate was formed after 1 h. The Raman spectroscopy analysis was performed.

scholarly journals Electrical characteristics of bismuth titanate glass-ceramics containing SiO2 and Nd2O3

2010 ◽  
Vol 4 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Stanislav Slavov ◽  
Milena Krapchanska ◽  
Elena Kashchieva ◽  
Yanko Dimitriev
Keyword(s):  
Electrical Properties ◽  
Glass Formation ◽  
Bismuth Titanate ◽  
Glass Ceramics ◽  
Sio2 Content ◽  
Electrical Characteristics ◽  
Frequency Range ◽  
Impedance Analyzer ◽  
Methods Of Synthesis ◽  
Titanate Ceramics

Bismuth-titanate ceramics containing SiO2 and Nd2O3 as additives are synthesized at two different ways of cooling of the melts. The introduction of SiO2 and Nd2O3 leads to more complex crystallization with participation of several phases including Bi4Ti3O12. It is proved that the applied methods of synthesis are suitable for generation of different microstructures in the bulk doped bismuth titanate ceramics, which is promising basis for modification of their electrical properties. The increasing of SiO2 content improves the glass formation ability and addition of Nd2O3 stimulates the crystallization. The conductivity of selected samples is determined by impedance analyzer in the frequency range from 10 to 100 kHz and DC resistible bridge using two-terminal method. All investigated samples are dielectrics with conductivity 10-6-10-9 (??cm)-1.

A solid-state route to stabilize cubic Li7La3Zr2O12 at low temperature for all-solid-state-battery applications

2020 ◽  
Vol 56 (96) ◽  
pp. 15197-15200
Author(s):  
Joah Han ◽  
Jae Chul Kim
Keyword(s):  
Solid State ◽  
Low Temperature ◽  
Solid State Reaction ◽  
Dense Microstructure ◽  
Solid State Route ◽  
Solid State Battery ◽  
B Doping

An additive-assisted solid-state reaction by Al and B doping enables cubic Li7La3Zr2O12 with a dense microstructure to be obtained at low temperature showing a reasonable Li conductivity.

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