scholarly journals Transport and Dielectric Properties of Mechanosynthesized La2/3Cu3Ti4O12 Ceramics

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 313
Author(s):  
Mohamad M. Ahmad ◽  
Hicham Mahfoz Kotb ◽  
Celin Joseph ◽  
Shalendra Kumar ◽  
Adil Alshoaibi
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Boundary Conductivity ◽  
X Ray ◽  
Giant Dielectric ◽  
Mechanochemical Milling ◽  
Giant Dielectric Constant ◽  
Lower Temperature

La2/3Cu3Ti4O12 (LCTO) powder has been synthesized by the mechanochemical milling technique. The pelletized powder was conventionally sintered for 10 h at a temperature range of 975–1025 °C, which is a lower temperature process compared to the standard solid-state reaction. X-ray diffraction analysis revealed a cubic phase for the current LCTO ceramics. The grain size of the sintered ceramics was found to increase from 1.5 ± 0.5 to 2.3 ± 0.5 μm with an increase in sintering temperature from 975 to 1025 °C. The impedance results show that the grain conductivity is more than three orders of magnitude larger than the grain boundary conductivity for LCTO ceramics. All the samples showed a giant dielectric constant (1.7 × 103–3.4 × 103) and dielectric loss (0.09–0.17) at 300 K and 10 kHz. The giant dielectric constant of the current samples was attributed to the effect of internal barrier layer capacitances due to their electrically inhomogeneous structure.

High-pressure x-ray diffraction study of the giant dielectric constant material CaCu3Ti4O12: Evidence of stiff grain surface

2006 ◽  
Vol 88 (19) ◽  
pp. 191903 ◽  
Author(s):  
Yanzhang Ma ◽  
Jianjun Liu ◽  
Chunxiao Gao ◽  
W. N. Mei ◽  
Allen D. White ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
High Pressure ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Giant Dielectric ◽  
Giant Dielectric Constant ◽  
Grain Surface

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.

Effects of 0.03MF2 – 0.12LiF (M = Ca, Sr, Ba) on the Sintering and Dielectric Properties of SrTiO3 Ceramics

2013 ◽  
Vol 9 ◽  
pp. 1-12
Author(s):  
Laldja Taïbi-Benziada ◽  
Hassiba Kermoun ◽  
Yasmina Belaroussi
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sintering Temperature ◽  
Cubic Phase ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Frequency Independent ◽  
Cold Pressed ◽  
Piezoelectric Devices

Cold-pressed pellets were prepared from the mixtures SrTiO3- 0.03MF2- 0.12LiF, M = Ca, Sr or Ba, then air-fired at 950 °C for 2 hours. The obtained samples were investigated by X-ray diffraction and scanning electron microscopy. Each ceramic is a perovskite single phase and the relative density reaches 95% for all ceramics. The addition of 3 mol. % of the eutectic composition 1MF2- 4LiF (Tm~ 760 °C) to SrTiO3lowers the sintering temperature of pure strontium titanate from 1400 °C to 950 °C and induces a strong modification in the SrTiO3cubic phase: superlattice reflections are detected and the unit cell symmetry becomes orthorhombic. Dielectric measurements were performed between - 150 °C and 200 °C in the frequency range 20 Hz - 109Hz. The dielectric permittivity εrshowed no maximum in the temperature range investigated and is almost frequency independent. At room temperature, the dielectric losses tanδ are less than 0.1 %. Moreover, the frequency dependence of the complex permittivity exhibits a resonance in the microwave region. These fluorinated ceramics could be of interest in piezoelectric devices and are promising dielectrics for class I capacitors manufactured at low temperature.

scholarly journals Effect of Zr4+ Content on Crystal Structure, Micromorphology and Dielectric Properties of Ba(Zrx Ti1-X)O3 Ceramics

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Great Influence ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Ba(Zrx Ti1-x)O3 ceramics (X=1.5, 2.0, 2.5, 3.0) were prepared by solid-state reaction method. Effect of controlling the ratio of Zr/Ti on the crystal structure, micromorphology and dielectric properties of BZT ceramics. Their crystal structures, morphologies, and electric properties were respectively characterized using X-ray diffraction, scanning electron microscope and impedance analyzer. The X-ray diffraction patterns show that the zirconium titanate ceramic samples behave cubic phase structure and no secondary phase. The ratio of Zr/Ti has a great influence on the crystal structure, microstructure and dielectric properties. As the Zr4+ content increases, the lattice constant increases and the grain size decreases. The dielectric constant is the largest when the Zr content is 15%. As the Zr4+ content increases, the dielectric constant decreases gradually, and the Curie temperature moves toward the low temperature region.

scholarly journals Effect of 45S5 bioactive glass on the sintering temperature of titanium-hydroxyapatite composite

2021 ◽  
Vol 1192 (1) ◽  
pp. 012021
Author(s):  
D S Abu Bakar ◽  
M G Kutty ◽  
N A Yahya
Keyword(s):  
Mechanical Properties ◽  
Bioactive Glass ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Volumetric Expansion ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Lower Temperature ◽  
Mechanical Properties And Corrosion

Abstract Titanium (Ti) is widely known for its good mechanical properties and corrosion resistance. However, it has poor biocompatibility. Hydroxyapatite (HA) is a biocompatible material but has poor mechanical properties. Making Ti-HA composite creates a promising choice of biomaterial in dental and medical applications. However, creating a Ti-HA composite requires sintering at high temperatures which leads to oxidation of Ti. The aim of this study was to reduce the sintering temperature of Ti-HA composite by incorporating 45S5 Bioactive Glass (BG) without compromising the chemical, physical and mechanical properties of the composite. In this study, a Ti-HA-BG composite with wt% of 45-45-10 respectively was produced via powder metallurgy. This was compared with the control composite consisting of 50 wt% Ti- 50 wt% HA. Powders according to the above-mentioned ratio were milled at 200 rpm for 5 hours by using a planetary ball milling machine. Samples were then compacted into cylindrical pellets via uniaxial pressing at 1500 psi and sintered in an atmospheric furnace at 1000 °C, 1100 °C and 1200 °C for 4 hours. Ti-HA and Ti-HA-BG sample characteristics were examined and compared by using Fourier Transformed Infrared Spectroscopy (FTIR), Energy Dispersive X-Ray (EDX) and X-Ray Diffraction (XRD). The density and volumetric expansion of the composites were also measured and compared. Results from XRD data indicate the reduction of oxidation of Ti and decomposition of HA in Ti-HA-BG composite at lower temperature in comparison to Ti-HA composite. The density of Ti-HA-BG composites are higher compared to Ti-HA composite while the volumetric expansion of Ti-HA-BG composites is lesser than Ti-HA composite. Therefore, BG is a low melting point additive that acts as a good sintering aid to effectively lower the sintering temperature while maintaining the desired properties of initial components.

scholarly journals Pembuatan Ba0,8Sr0,2TiO3 menggunakan Metode Co-precipitation dengan Variasi Suhu Sintering

2017 ◽  
Vol 7 (1) ◽  
pp. 51
Author(s):  
Isma Alvia Nita ◽  
Yofentina Iriani ◽  
Fahru Nurosyid
Keyword(s):  
Dielectric Constant ◽  
Crystal Size ◽  
Sintering Temperature ◽  
Microstructure Characterization ◽  
Temperature Measurements ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lcr Meter ◽  
Co Precipitation

<p>Ba<sub>0,8</sub>Sr<sub>0,2</sub>TiO<sub>3 </sub>was made by co-precipitation method with the sintering temperature of 600<sup>o</sup>C, 700<sup>o</sup>C, 800<sup>o</sup>C and 900<sup>o</sup>C for 4 hours. Sintering temperature was varied to investigate its effect on microstructure and dielectric constant of Ba<sub>0,8</sub>Sr<sub>0,2</sub>TiO<sub>3</sub>. microstructure characterization was performed by X-Ray Diffraction (XRD) instrument. Dielectric constant characterization was perform by LCR meter. The crystal size increased significantly with increasing sintering temperature. Measurements of dielectric constant were performed at range of frequency 0.01 to 100 KHz. Dielectric constant value is highest at the lowest frequency. Dielectric constant value size increased significantly with increasing sintering temperature.</p>

scholarly journals Sintesis Ferroelektrik BaZrxTi1-xO3 Dengan Variasi Zirkonium Terhadap Struktur Kristal dan Konstanta Dielektrik

2021 ◽  
Vol 9 (1) ◽  
pp. 47-54
Author(s):  
Yunita Subarwanti ◽  
◽  
Erni Mariana ◽  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Dielectric Constant ◽  
Die Pressing

This study aims to determine influence addition Zr against the crystal structure and dielectric constant; and to know the influence of variations temperature sintering on addition mole Zr. Barium Zirconium Titanate (BaZrxTi1-xO3) have been made with variation zirconium (Zr) 1%, 5%, 10%, and 20% by solid state reaction method, that is blanded BaTiO3, TiO2 and ZrO2 powder. BaZrxTi1-xO3 powder is printed with die pressing and press hidrolik, then the samples were sintered by furnace at 900oC and 1000oC with holding time 2 hours. Characterization of samples use X-Ray Diffraction and Resistance Capacitance Inductance (RCL meter). Based on result obtained, the larger Zr content cause dielectric constant decreasing because crystal structure have been change from tetragonal (Zr = 1% and 5%) to cubic (Zr = 10% and 20%). The result from X-Ray Diffraction already match with data base ICDD no#360019. Measurement of dielectric constant (K) performed in the frequency range 1 kHz to 100 kHz and the highest value at Zr content 1%, because The dielectric constant decreasing with the larger Zr content. The maximum dielectric constant is obtained at mol Zr 5% and sintering temperature 1000oC, that is 150. The minimum dielectric constant is obtained at mol Zr 20% and sintering temperature 900oC, that is 62.

scholarly journals Sintering of cordierite in the presence of MoO3 and crystallization analysis

2014 ◽  
Vol 46 (3) ◽  
pp. 307-313 ◽  
Author(s):  
N. Djordjevic ◽  
N. Obradovic ◽  
D. Kosanovic ◽  
M. Mitric ◽  
V.P. Pavlovic
Keyword(s):  
Binary Systems ◽  
Sintering Temperature ◽  
Preparation Process ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Temperature ◽  
Cordierite Ceramics ◽  
Low Temperature Process

Cordierite (MAS) is difficult to sinter because of the very narrow sintering temperature range (1300-1400?C). Because a low temperature process is desirable, it is necessary to find functional ads which can allow easier sintering process at lower temperature. The influence of MoO3 on the preparation process of cordierite ceramics was investigated. 2MgO-2Al2O3-5SiO2 was researched by sintering followed binary systems: MgO/MoO3, Al2O3/MoO3 and SiO2/MoO3 (all sintered at 850?C and 1100?C, sintering time 2h). Composition of these systems was 80 mass% of oxide and 20 mass% MoO3. The effects of sintering, the composition and morphology were followed by X-ray diffraction and SEM microscopy. It has been found that MoO3, beside liquid phase, forms intermediary unstable compounds with MgO and Al2O3, which is the significance information for further research. MAS ceramics were sintered with 20 mass% MoO3 at 1100?C, 1200?C and 1300?C, during 2h.

Preparation and Dielectric Properties of Li2O Doped BaZr0.25Ti0.75O3 Ceramics

2011 ◽  
Vol 284-286 ◽  
pp. 1460-1465
Author(s):  
Di Chen ◽  
Xiang Yun Deng ◽  
Jian Bao Li ◽  
Li Ming Wang ◽  
Xin Zheng Wu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
Sintering Aid ◽  
X Ray ◽  
Ceramic Process ◽  
Low Sintering Temperature

BaZr0.25Ti0.75O3(BZT) ceramics were prepared by conventional ceramic process at a relatively low sintering temperature and with an addition of Li2O as the liquid-phase sintering aid. X-ray diffraction characterized results showed that the main crystal phase of the samples with 1.0wt% Li2O additive sintered at 1050°C～1250°C for 4h presented perovskite structure. The dielectric properties of BZT ceramics have been investigated. The dielectric constant of 1.0wt% Li2O doped BZT sintered at 1150°C decreased, and the dielectric loss increased by 0.0012 compared with that of the pure BZT sintered at 1450°C.

scholarly journals INVESTIGATION ON PHYSICAL AND ELECTRICAL PROPERTIES OF THE SiO2-ZnO NANOCOMPOSITE AT DIFFERENT COMPOSITION MIXINGS

2018 ◽  
Vol 10 (1) ◽  
pp. 18
Author(s):  
Moh. Sinol ◽  
Erika Rani
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Mixing Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixing Method ◽  
The Difference ◽  
New Phase

<p>Physical and electrical properties of The SiO<sub>2</sub>-ZnO mixing at different compositions were investigated. The experiment used simple mixing method at the sintering temperature 600<sup>o</sup>C. It was used the composition mixing ratio of SiO<sub>2</sub>:ZnO ie. 0<strong>:</strong>10; 7<strong>:</strong>3; 5<strong>:</strong>5; 3<strong>:</strong>7; and 10:0 (%Wt)<sub>. </sub>Based on X-Ray Diffraction (XRD) results, it obtained that a new phase in each sample was not formed even though having different diffraction peak. The mixing ratio of SiO<sub>2</sub>: ZnO nanocomposite (7:3 %wt) had the biggest grain size (77,92 nm), the highest dielectric constant (3.00E+05) and the smallest conductivity (0,726549 (Ωm)<sup>-1</sup>). On the other side, the mixing ratio of SiO<sub>2</sub>: ZnO nanocomposite (5:5 %wt) had the smallest grain size (35.42nm), dielectric constant (3.00E+2) and the highest conductivity (25.36729  (Ωm)<sup>-1</sup>). It can be concluded that the difference of composition ratio offered the change on both physical and electrical properties of SiO<sub>2</sub>-ZnO nanocomposite. </p>

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