Effect of Calcination Temperature on the Breakdown Strength and Energy Density of CaCu3Ti4O12 Ceramic

2017 ◽  
Vol 888 ◽  
pp. 23-27 ◽  
Author(s):  
Mohd Fariz Ab Rahman ◽  
Mohamad Johari Abu ◽  
Rosyaini Afindi Zaman ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
...  
Keyword(s):  
Grain Size ◽  
Energy Density ◽  
Calcination Temperature ◽  
Single Phase ◽  
Breakdown Strength ◽  
Raw Materials ◽  
Sintered Sample ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Secondary Phases

The effect of calcination temperature on the breakdown strength and energy density of CaCu3Ti4O12 (CCTO) ceramics was studied. CCTO ceramics were prepared via solid state reaction method. The raw materials of CCTO were wet mixed for 24 hours and then dried overnight in oven. CCTO mixtures were calcined at three different temperature which is at 900°C, 930°C and 950°C for 12 hours. The calcined powders were compacted at 250 MPa and then were sintered at 1040°C for 10 hours. X-Ray Diffractometer (XRD) analysis showed the formation of CCTO phase and secondary phases of CuO and CaTiO3 for C900 calcined powders but single phase of CCTO was obtained by C930 and C950 calcined powders. Single phase of CCTO also were seen for all sintered samples. Observation on Scanning Electron Microscopy (SEM) micrographs showed large grain size was seen in C900 sintered sample and finer grain size was observed for C930 and C950 sintered samples. C900 sintered sample obtained highest dielectric constant (8617), highest breakdown strength (7.92 kV/cm), highest energy density (2.392 J/cm3).

scholarly journals The investigation of electrical properties and microstructure of ZnO-doped Ba0.9Sr0.1TiO3 ceramics

2017 ◽  
Vol 07 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Gang Liu ◽  
Wentao Jiang ◽  
Jingyong Jiao ◽  
Li Liu ◽  
Ziyang Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Electrical Breakdown Strength

Ba[Formula: see text]Sr[Formula: see text]TiO3 ceramics with or without ZnO have been prepared by traditional solid state reaction method. The XRD analysis showed that the doped Zn[Formula: see text] ions diffused into the BST crystal lattice, resulting in the variation of dielectric properties. Especially the dielectric constant at Curie point decreased with doping ZnO content when it is lower than 0.5[Formula: see text]mol%. Due to the promotion of sintering, doping ZnO can enhance the density of ceramics but increase grain size. However, ZnO is a kind of semiconductor and can lead to the decrease in electrical breakdown strength value.

Synthesis, Characterization and Electrical Properties of Single Phase La0.9Sr0.1Ga0.8Mg0.2O3

2010 ◽  
Vol 636-637 ◽  
pp. 874-879
Author(s):  
Anna Gaki ◽  
G. Kakali ◽  
R.J. Wiglusz ◽  
W. Strek ◽  
Grzegorz Paściak
Keyword(s):  
Grain Size ◽  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Single Phase ◽  
Sintered Sample ◽  
Polymeric Precursor ◽  
Secondary Phases ◽  
Sem Images ◽  
Xrd Pattern ◽  
Precursor Route

Single phase La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM9182) was synthesized by a polymeric precursor route. The XRD pattern after calcination at 1300 °C for 6h indicates the formation of the perovskite without the presence of secondary phases. XRD, FTIR and TG-DTG measurements were used to examine the powder precursor as well as the intermediate and final products. SEM images indicated the small grain size of the final product. The conductivity of the sintered sample was examined by means of a.c. impedance spectroscopy and was found to be 9.10-2 S/cm at 800 °C similar to the typical value of LSGM materials.

Structural, Dielectric and Electrical Studies of Ba4CaRTi3Nb7O30 (R = Eu, Dy) Ferroelectric System

2013 ◽  
Vol 547 ◽  
pp. 41-48 ◽  
Author(s):  
Prasun Ganguly ◽  
A.M. Biradar ◽  
A.K. Jha
Keyword(s):  
Single Phase ◽  
Microstructural Analysis ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Paraelectric Phase Transition ◽  
Orthorhombic Crystal Structure

The polycrystalline samples of Ba4CaRTi3Nb7O30 (R = Eu, Dy), members of tungsten-bronze family, were prepared by high-temperature solid state reaction method and studied for their dielectric and electrical properties. X-ray diffraction (XRD) analysis reveals the formation of single-phase compounds having orthorhombic crystal structure at room temperature. Microstructural analysis by scanning electron microscope (SEM) shows that the compounds have well defined grains, which are distributed uniformly throughout the sample. Detailed dielectric properties of the compounds as a function of frequency and temperature show that the compounds undergo non-relaxor kind of ferroelectric-paraelectric phase transition of diffuse nature. Ferroelectric, piezoelectric and pyroelectric studies of the compounds have been discussed in this paper. The temperature dependence of dc conductivity of the compounds have been investigated. The conductivity study over a wide temperature range suggests that the compounds have negative temperature coefficient of resistance (NTCR) behaviour.

Development of Patch Antenna Substrate in BaO-4.TiO2 System

2015 ◽  
Vol 830-831 ◽  
pp. 425-428
Author(s):  
Hariharan Sreemoolanadhan ◽  
Basheer Masin ◽  
Mariamma Mathew ◽  
S.C. Sharma
Keyword(s):  
Patch Antenna ◽  
Raw Materials ◽  
Xrd Analysis ◽  
Decomposition Reaction ◽  
Q Factor ◽  
Secondary Phases ◽  
Solid State Method ◽  
Practical Applications ◽  
Temperature Coefficient Of Frequency ◽  
State Method

BaTi4O9(BT4), has dielectric constant (εr)≈36 and unloaded Q-factor (Qf) >35,000GHz, but has temperature coefficient of frequency (τf~16-20ppm/°C). Ba2Ti9O20(B2T9), very near to BT4 in the BaO-TiO2phase diagram, has εr~38, Qf~35,000GHz and τf<4ppm/°C. Though this phase is selected for most of the applications, there are many challenges like slow formation, decomposition, reaction with substrate etc. But, BT4 formed quickly and densified easily, but only high τf precluded it from many practical applications. Most of the literature on the modification of BT4 decreased the εr≤35. Here, the preparation and properties of ZnO/ZnTiO3added BaTi4O9ceramics are reported. The ceramics have been prepared by the solid state method. Raw materials have been homogenized and calcined at 1125°C. Calcined powders are ball-milled, compacted and sintered in 1275−1350°C to get dense ceramics with ρ=4.38-4.44 g/cc (TD>97.5%). XRD analysis has confirmed the BaTi4O9phase formation along with secondary phases. FeSEM microstructures show liquid phase assisted sintering leading to fused grains and exaggerated grain growth. The dielectric properties have been measured near 4GHz by standard rod resonator methods using cylindrical specimens. The ceramics have εr36.5−38, τf<11ppm/°C and Qf>17THz. It is possible to further improve the Qf of these ceramics by controlling the processing.

DIELECTRIC STUDIES OF SAMARIUM MODIFIED (Pb)(Zr, Ti, Fe, Nb)O3 CERAMIC SYSTEM

2009 ◽  
Vol 23 (11) ◽  
pp. 1437-1442 ◽  
Author(s):  
PRATIBHA SINGH ◽  
SANGEETA SINGH ◽  
J. K. JUNEJA ◽  
CHANDRA PRAKASH ◽  
K. K. RAINA
Keyword(s):  
Dielectric Constant ◽  
Room Temperature ◽  
Single Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Dielectric Studies ◽  
Dielectric Measurements ◽  
Ceramic System ◽  
Reaction Method ◽  
Room Temperature Dielectric Constant

Here we report the investigations on Sm -substituted PZTFN ( Pb 1-x Sm x Zr 0.588 Ti 0.392 Fe 0.01 Nb 0.01 O 3) (where x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) polycrystalline solid solutions fabricated by solid-state reaction method. XRD analysis shows all the samples to be single phase with tetragonal structure. Dielectric measurements were carried out in the temperature range 30°C–400°C at different frequencies in the range 100 Hz to 100 kHz. From the temperature variation of dielectric constant (ε), Curie temperature (TC) was determined which was found to decrease with increasing x. The room temperature dielectric constant (ε RT ) initially increases with increasing x and then starts decreasing. Dielectric loss improves with Sm -doping.

Densification of Aluminum Nitride Ceramics with CaF2 Additive

2008 ◽  
Vol 368-372 ◽  
pp. 970-972 ◽  
Author(s):  
Yan Xiong ◽  
Zheng Yi Fu ◽  
Hao Wang
Keyword(s):  
Grain Size ◽  
Aluminum Nitride ◽  
Secondary Phase ◽  
Phase Evolution ◽  
Sintered Sample ◽  
Nitrogen Atmosphere ◽  
Microstructural Development ◽  
Secondary Phases ◽  
Nitride Ceramics ◽  
Sem Investigation

Effect of adding up to 5wt% CaF2 on the densification and microstructural development of hot pressed aluminum nitride (AlN) was investigated. SEM investigation showed that the grain size of the sintered sample decreases with the increasing content of CaF2. Secondary-phase evolution paths converge from CA6 to CA phase above 1650°C. TEM micrographs showed that formed secondary phases could evaporate from sintered bodies at higher temperatures in the carbon-containing nitrogen atmosphere and the residuals were mainly distributed at triple grain junctions, keeping direct connections of AlN grains. Translucnet AlN ceramics were prepared using CaF2 additive sintered at 1850°C for 5 h.

scholarly journals Dielectric, ferroelectric and magnetic properties of Bi0.78La0.08Sm0.14Fe0.85Ti0.15O3 ceramics prepared at different sintering conditions

2018 ◽  
Vol 12 (4) ◽  
pp. 394-402 ◽  
Author(s):  
Zhengxin Li ◽  
Zhenhua Wang ◽  
Rongli Gao ◽  
Wei Cai ◽  
Gang Chen ◽  
...  
Keyword(s):  
Structural Changes ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Grain Morphology ◽  
Solid State Reaction Method ◽  
Secondary Phases ◽  
Conventional Solid State Reaction ◽  
Multiferroic Properties ◽  
Co Doping ◽  
Sintering Time

Although BiFeO3 (BFO) has attracted great attention due to its special physical properties as a typical single phase multiferroic material, the application is limited due to the formation of impurities, defects and so forth. Herein, we report improved multiferroic properties of Bi0.78La0.08Sm0.14Fe0.85Ti0.15O3 (BLSFTO) ceramics by combination of co-doping and sintering schedule. BLSFTO multiferroic ceramics were prepared by using the conventional solid state reaction method and the effect of sintering time (2, 5, 10, 20 and 30 h) on the structural, dielectric and multiferroic properties was investigated systematically. The result indicates that stable BLSFTO phase with perovskite structure was formed for all the samples. Only some impurities such as Bi2O4 can be observed when the sintering time is longer than 20 h, indicating that the sintering time can induce structural changes in BLSFTO and too long sintering time can remarkably increase the secondary phases. In addition, the frequency dependent dielectric properties show that sintering time has distinct effect on the frequency stability and the relaxation process. The result demonstrates that the enhanced magnetization, improved dielectric and ferroelectric properties may be correlated with the structural transformation, impurities, oxygen vacancies and grain morphology.

Preparation of Aluminum Oxynitride Powder by Solid State Reaction Method

2008 ◽  
Vol 368-372 ◽  
pp. 435-437 ◽  
Author(s):  
Jin Song Wen ◽  
Tie Cheng Lu ◽  
Jian Qi Qi ◽  
Ji Cheng Zhou ◽  
Wei Pang ◽  
...  
Keyword(s):  
Phase Composition ◽  
Solid State ◽  
Single Phase ◽  
Raw Materials ◽  
Solid State Reaction Method ◽  
Aluminum Oxynitride ◽  
Reaction Method ◽  
Weight Percentage ◽  
Α Al2o3 ◽  
Holding Temperature

Single-phase aluminum oxynitride powders were obtained by varying the holding temperature (T) and the weight percentage of α-Al2O3 in Al2O3 (X) with nano-sized Al2O3 and AlN powders as raw materials. Influences of T and X on the phase composition of obtained powders were studied. The results showed that the content of aluminum oxynitride increased with increasing T or X. When X was 50% and T was 1750°C, obtained powders had better properties than those of others.

The Effect of CuO on NiO Electroceramics

2015 ◽  
Vol 1107 ◽  
pp. 3-8
Author(s):  
Tan Guan Kui ◽  
Mohd Fariz Ab Rahman ◽  
Zainal Arifin Ahmad ◽  
Julie Juliewatty Mohamed
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Single Phase ◽  
Dopant Concentration ◽  
Raw Materials ◽  
Density Measurement ◽  
Lattice Parameter ◽  
Impedance Analyzer ◽  
Cu Dopant ◽  
Pellet Form

The Ni1-xCuxO was prepared from raw materials of NiO and CuO via solid state reaction. This study was focuses on undoped and CuO doped NiO properties. CuO was used as dopant with five different concentrations. The powders were mix for 24 hours and followed by calcinations at 900°C for 2 hours. The calcined powders were compacted to a 5 mm diameter pellet form, by applying 200 MPa pressure. Then, the pellets were sintered at temperature 1200°C for 12 hours. After that, the samples were analyzed by using XRay diffraction (XRD) in order to identify the phase formation, scanning electron microscopy (SEM) for the microstructure and surface topography observation, density measurement by Archimedes principle and impedance analyzer in order to measure the dielectric properties. XRD results show that all sintered pellets produce a single phase of Ni1-xCuxO. In addition, increase of Cu dopant concentration causes the lattice parameter getting larger. Apart from that, SEM shows that more addition of Cu dopant increase the grain size. The density is also improved, due to formation of bigger grain size lead to an increasing in density. Impedance analyzer results show the dielectric behaviour of the samples was improved with increasing of CuO content. The 0.10 mol% CuO obtained optimum dielectric properties with lowest dielectric loss measured at 1 GHz (0.008).

Towards a Silicate Matrix for the Immobilisation of Halide-rich Wastes

2013 ◽  
Vol 1518 ◽  
pp. 91-96 ◽  
Author(s):  
M. R. Gilbert
Keyword(s):  
Solid Solutions ◽  
Single Phase ◽  
Xrd Analysis ◽  
Inert Atmosphere ◽  
Secondary Phases ◽  
Silicate Matrix ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Trivalent Actinides

ABSTRACTSingle-phase calcium chlorosilicate and sodalite, two potential ceramic waste-forms for the immobilisation of CaCl2-based pyroprocessing wastes, have been fabricated at temperatures below the volatilisation point of CaCl2. Solid solutions doped with Sm3+ as an inactive analogue for trivalent actinides have been fabricated and characterised. XRD analysis shows both phases will successfully accommodate Sm3+, with the sodalite in particular remaining single-phase. Fabrication of Sm-doped calcium chlorosilicate in air results in the formation of SmOCl and Ca(Si2O5) secondary phases, however, calcination in an inert atmosphere is shown to successfully retard the formation of SmOCl allowing for higher levels of doping.

Sign in / Sign up

Export Citation Format

Share Document