scholarly journals Evaluation of the Microstructure and the Electrochemical Properties of Ce0.8(1−x)Gd0.2(1−x)CuxO[1.9(1−x)+x] Electrolytes for IT-SOFCs

2020 ◽  
Vol 10 (13) ◽  
pp. 4573 ◽  
Author(s):  
Grazia Accardo ◽  
Jae Kwan Bae ◽  
Sung Pil Yoon
Keyword(s):  
Crystal Structure ◽  
Electrochemical Properties ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Secondary Phase ◽  
Total Conductivity ◽  
Temperature Range ◽  
Copper Addition ◽  
Dense Bodies

The influence of copper addition (0.5–2 mol%) on the crystal structure, densification microstructure, and electrochemical properties of Ce0.8Gd0.2O1.9 synthesized in a one-step sol–gel combustion synthesis route has been studied. It has been found that Cu is very active as sintering aids, with a significative reduction of GDC firing temperature. A reduction of 500 °C with a small amount of copper (0.5 mol%) was observed achieving dense bodies with considerable ionic conductivities. Rietveld refined was used to investigate the crystal structure while relative density and microstructural examination were performed in the sintering temperature range of 1000–1200 °C after dilatometer analysis. High dense bodies were fabricated at the lowest sintering temperature, which promotes the formation of Ce0.8(1−x)Gd0.2(1−x)CuxO[1.9(1−x)+x] solid solution and the absence of secondary phase Cu-rich or the segregation or copper at the grain boundary. As compared to the pure GDC an improvement of total conductivity was achieved with a maximum for the highest copper content of 2.23·10−3–9.19·10−2 S cm−1 in the temperature range of 200–800 °C.

Preparation of TiO2 Thin Films by Sol-Gel Method and Analysis of its Transmittance Based on Computer Image Processing

2020 ◽  
Vol 842 ◽  
pp. 121-126
Author(s):  
Ji Hui Luo ◽  
Qiu Yue Wen ◽  
Shu Liu ◽  
Ting Liu ◽  
Su Ting Wei ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Light Transmittance ◽  
Anatase Structure ◽  
Gel Method ◽  
Sol Gel Method ◽  
Computer Image Processing ◽  
Imagej Software

TiO2 films were prepared by sol-gel method with butyl titanate, anhydrous ethanol, acetyl acetone and hydrochloric acid as raw materials, which were sintered at 380 °C and 530 °C respectively to obtain TiO2 films. XRD was used for analyzing the crystal structure of TiO2 film, and ImageJ software was used to detect the light transmittance of TiO2 film samples. The results show that the film sintered at 530 °C is brookite structure and the film sintered at 380 °C is anatase structure. The increase of sintering temperature is not conducive to the growth of TiO2 film grains. TiO2 films sintered at 380 °C have good light transmittance.

Phase Composition and Microstructure of Ca1–3xLn2xTiO3 (Ln=La, Nd, Sm) Ceramics

2012 ◽  
Vol 430-432 ◽  
pp. 36-40
Author(s):  
Bing Liang Liang ◽  
Yun Long Ai ◽  
Xing Hua Zheng ◽  
De Ping Tang ◽  
Fei He
Keyword(s):  
Crystal Structure ◽  
Phase Composition ◽  
Relative Density ◽  
Growth Pattern ◽  
Perovskite Structure ◽  
Sintering Temperature ◽  
Secondary Phase ◽  
Xrd Analysis ◽  
Structure Phase ◽  
Structure And Microstructure

Ca1–3xLn2xTiO3 (Ln=La, Nd, Sm; x=0.13, 0.20) ceramics were investigated systematically to dicuss the influences of sintering temperature, compositions, Ln3+ ions on its sintering property, crystal structure and microstructure. The results show that the dense ceramics were obtained in the sintering temperature range of 1300~1350 °C and the relative density reached over 97%. Sintering temperature was 50~150 °C lower than previous reports. Single orthogonal perovskite structure phase was formed except that a little secondary phase Sm2Ti2O7 was detected by XRD analysis when x=0.20 and Ln=Sm. The growth pattern of Ca1–3xLn2xTiO3 grains was terracing growth.

scholarly journals Role of sintering temperature dependent crystallization of bioactive glasses on erythrocyte and cytocompatibility

2019 ◽  
Vol 13 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Shivalingam Chitra ◽  
Purushothaman Bargavi ◽  
Dhinasekaran Durgalakshmi ◽  
Padmanaban Rajashree ◽  
Subramanian Balakumar
Keyword(s):  
Mechanical Property ◽  
Structural Analysis ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Secondary Phase ◽  
Phase Changes ◽  
Temperature Dependent ◽  
Bioactive Glasses ◽  
Secondary Phase Formation

Bioglass (BG) was prepared by sol-gel method and the role of sintering temperatures (600, 700 and 800?C) on crystalline phase changes, bioactivity, erythrocyte andMG-63 cell line compatibility was investigated. Increase in sintering temperature from 600 to 800?C led to the secondary phase formation that was confirmed through structural analysis. Micrographics revealed the formation of nanorods (700?C) and nanoflake like (800?C) morphologies. Biocompatibility assay showed that, BG sintered at 600?C had optimal biocompatibility while better mechanical property was noted at 700?C. Altogether, the study demonstrated that increasing the sintering temperature will result in increased crystallinity which in turn resulted in the optimal biomineralization but decreased the biocompatibility. Hence, we demonstrated the importance of temperature during the processing of BG for various applications, as it affects many properties including bioactivity and compatibility.

scholarly journals Giant dielectric response in microwave processed CaCu3Ti4O12 ceramics: A correlation among microstructure, dielectric and impedance properties

2019 ◽  
Vol 13 (4) ◽  
pp. 387-400
Author(s):  
Buddhadev Samanta ◽  
Dipika Nanda ◽  
Pawan Kumar ◽  
Rashmirekha Sahu ◽  
Sujata Swain ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Grain Boundary ◽  
Sintering Temperature ◽  
Heterogeneous Systems ◽  
Secondary Phase ◽  
Rietveld Analysis ◽  
Boundary Region ◽  
Microstructural Investigation ◽  
Giant Dielectric ◽  
Different Temperatures

Polycrystalline CaCu3Ti4O12 (CCTO) ceramics was synthesized by microwave assisted solid-state reaction. Effect of sintering at different temperatures on the crystal structure, dielectric and impedance properties was investigated in detail. Rietveld analysis of X-ray diffraction data identified that crystal structure was a mixture of cubic CCTO and monoclinic CuO phases. Lattice parameters and amount of CuO secondary phase were also estimated as a function of sintering temperature. Microstructural investigation confirmed the existance and successive increase of the melted phase near the grain boundary region with increasing temperature of sintering. Cu-rich nature of the melted phase was further confirmed by selective area EDX spectra. Dielectric and impedance properties were studied as a function of frequency (100Hz to 1MHz) and temperature (room temperature to 300?C). Improvement in dielectric properties as a function of sintering temperature (1000 to 1050?C) was explained in terms of reduction in grain boundary dimension due to the successive increase in Cu-rich melted phase. However, dielectric constant started falling when sintered at 1075?C, which may be accounted in terms of segregation of large amount of CuO phase after a certain temperature and hence a non-stoichiometry of Cu in CCTO lattice. Impedance data were modelled by equivalent electrical circuits to investigate different contributions of electrically heterogeneous systems. In addition, probable relaxationmechanism has been discussed on the basis of impedance and modulus data. Activation energies were calculated from different characterizations and a non-Debye-type relaxation phenomena were observed. In this work, an attempt is made to build up a correlation among synthesis procedure, sintering temperature, dielectric, impedance and microstructural properties.

Influence of microstructure and AlPO4 secondary-phase on the ionic conductivity of Li1.3Al0.3Ti1.7(PO4)3 solid-state electrolyte

2016 ◽  
Vol 09 (05) ◽  
pp. 1650066 ◽  
Author(s):  
Shicheng Yu ◽  
Andreas Mertens ◽  
Xin Gao ◽  
Deniz Cihan Gunduz ◽  
Roland Schierholz ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Secondary Phase ◽  
Lithium Aluminum ◽  
Phase Content ◽  
Solid State Electrolyte ◽  
Ceramic Electrolyte

A ceramic solid-state electrolyte of lithium aluminum titanium phosphate with the composition of Li[Formula: see text]Al[Formula: see text]Ti[Formula: see text](PO[Formula: see text] (LATP) was synthesized by a sol–gel method using a pre-dissolved Ti-source. The annealed LATP powders were subsequently processed in a binder-free dry forming method and sintered under air for the pellet preparation. Phase purity, density, microstructure as well as ionic conductivity of the specimen were characterized. The highest density (2.77[Formula: see text][Formula: see text] with an ionic conductivity of [Formula: see text] (at 30[Formula: see text]C) was reached at a sintering temperature of 1100[Formula: see text]C. Conductivity of LATP ceramic electrolyte is believed to be significantly affected by both, the AlPO4 secondary phase content and the ceramic electrolyte microstructure. It has been found that with increasing sintering temperature, the secondary-phase content of AlPO4 increased. For sintering temperatures above 1000[Formula: see text]C, the secondary phase has only a minor impact, and the ionic conductivity is predominantly determined by the microstructure of the pellet, i.e. the correlation between density, porosity and particle size. In that respect, it has been demonstrated, that the conductivity increases with increasing particle size in this temperature range and density.

Preparation and Relaxor Behavior of Barium Strontium Titanate Glass-Ceramics Doped Si-B-O Sintered from Sol-Gel Derived Powders

2011 ◽  
Vol 687 ◽  
pp. 370-374
Author(s):  
Jiang Ying Wang ◽  
Jing Ji Zhang
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Secondary Phase ◽  
Relaxor Behavior ◽  
Dense Microstructure ◽  
Ionic Substitution ◽  
Barium Strontium ◽  
Dielectric Peak ◽  
Type Relation

The structural and dielectric properties of Si-B-O doped Ba0.60Sr0.40TiO3(BST) glass-ceramics prepared by using sol-gel derived powders have been investigated. The secondary phase of BaTi2Si2O8is clearly observable in BST glass-ceramics when the concentration of Si-B-O is equal to or more than 20mol%. The samples with high Si-B-O doping levels can be sintered into dense microstructure in low sintering temperature (below 1000°C). The dielectric peaks of BST glass-ceramics are markedly suppressed, broadened and shifted to low temperature with increasing the concentration of Si-B-O, accompanying an increased diffuseness of the dielectric peak due to the ionic substitution, which follows well the Lorenz-type relation.

Preparation and Characterization of Citrate Sol-Gel Derived Ba(Zr,Ti)O3 Ceramics with Al2O3 Addition

2007 ◽  
Vol 336-338 ◽  
pp. 76-78
Author(s):  
Jing Pei ◽  
Zhen Xing Yue ◽  
Fei Zhao ◽  
Zhi Lun Gui ◽  
Long Tu Li
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Sintering Behavior ◽  
Gel Method ◽  
Sol Gel Method

The nano-sized Ba(Zr0.2Ti0.8)O3 powder was prepared by citrate sol-gel method. The crystal structure and the particle size of the powder were characterized by XRD. The morphology of calcined powder and the sintered ceramics was observed by TEM and SEM, respectively. The particle size of the powders calcined at 600oC is about 10 nm. The dense ceramics can be obtained at sintering temperature of 1220 oC, which is much lower than that of the powder prepared by the conventional solid method. The effects of Al2O3 additive on the sintering behavior, microstructure and dielectric properties of Ba(Zr0.2Ti0.8)O3 ceramics were also investigated.

The Influence of Sintering Temperature on the Microstructure and Electrical Properties of BiFeO3 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 942-946
Author(s):  
Xiao Ling Deng ◽  
Xing Bing Liu ◽  
Wei Cai ◽  
Chun Lin Fu ◽  
Jia Mu Huang
Keyword(s):  
Crystal Structure ◽  
Point Defects ◽  
Sintering Temperature ◽  
Bismuth Ferrite ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Impurity Phase ◽  
Molar Ratio ◽  
Vacancy Defects ◽  
Structure Morphology

This study reports the synthesis of bismuth ferrite ceramics (BiFeO3, BFO) by the sol-gel method and the effect of different sintering temperatures (800 °C, 820 °C, 850 °C, 880 °C, 900 °C) on the crystal structure, morphology, dielectric properties and ferroelectric properties of the bismuth ferrite ceramics. It is observed that the bismuth ferrite phase are formed when the molar ratio of bismuth and ferric is 1.025 : 1, and the bismuth ferrite ceramics have less impurity phase at all the five sintering temperature. The morphology studies revealed that the grain of bismuth ferrite ceramics is spherical and the grain size increases with the increasing of the sintering temperature. When the bismuth ferrite ceramics with excessive bismuth sintered at 820 °C, it exhibits the higher dielectric constant and the lower dielectric loss, the remnant polarization and the coercive field are 0.35 μC/cm2 and 4.03kV/cm, respectively. The observed ferroelectricity in bismuth ferrite ceramics owes to the point defects associated with oxygen vacancy defects as well as the smaller size effect.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals Surface Chemistry, Crystal Structure, Size and Topography Role in the Albumin Adsorption Process on TiO2 Anatase Crystallographic Faces and Its 3D-Nanocrystal: A Molecular Dynamics Study

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 420
Author(s):  
Giuseppina Raffaini
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Surface Chemistry ◽  
Protein Adsorption ◽  
Adsorption Process ◽  
Sol Gel ◽  
Interaction Strength ◽  
Theoretical Work ◽  
Blood Protein ◽  
Tio2 Anatase

TiO2 is widely used in biomaterial implants. The topography, chemical and structural properties of titania surfaces are an important aspect to study. The size of TiO2 nanoparticles synthetized by sol–gel method can influence the responses in the biological environment, and by using appropriate heat treatments different contents of different polymorphs can be formed. Protein adsorption is a crucial step for the biological responses, involving, in particular, albumin, the most abundant blood protein. In this theoretical work, using molecular mechanics and molecular dynamics methods, the adsorption process of an albumin subdomain is reported both onto specific different crystallographic faces of TiO2 anatase and also on its ideal three-dimensional nanosized crystal, using the simulation protocol proposed in my previous theoretical studies about the adsorption process on hydrophobic ordered graphene-like or hydrophilic amorphous polymeric surfaces. The different surface chemistry of anatase crystalline faces and the nanocrystal topography influence the adsorption process, in particular the interaction strength and protein fragment conformation, then its biological activity. This theoretical study can be a useful tool to better understand how the surface chemistry, crystal structure, size and topography play a key role in protein adsorption process onto anatase surface so widely used as biomaterial.

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