Sol-Gel Synthesis of Solid Solution Based on Cerate-Zirconate Ceramics

2019 ◽  
Vol 290 ◽  
pp. 29-34
Author(s):  
Osman Nafisah ◽  
Abdul Samat Abdullah ◽  
Wan Zuliana Wan Zulkifli ◽  
Mahendra Rao Somalu ◽  
Andanastuti Muchtar ◽  
...  
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Reactor System ◽  
Critical Parameters ◽  
Processing Temperature ◽  
Barium Cerate ◽  
Phase Purity ◽  
Calcination Temperatures ◽  
Single Perovskite Phase

Ceramics powders based on cerate-zirconate such as yttrium-doped barium cerate-zirconate, BaCe0.54Zr0.36Y0.1O3 (BCZY) have been used as electrolyte materials for proton-conducting fuel cell (PCFC) application. High purity of the ceramics powders are traditionally prepared by solid state reaction (SSR) method at a high processing temperature (> 1400 °C). Alternatively, sol-gel (SG) technique and high pressure – high temperature (HP-HT) batch wise reactor system using supercritical fluids (SCFs) method are introduced to synthesis the powders at a lower temperature. To achieve the goals in producing the ceramics powders with better properties than SSR method, few critical parameters for both SG and SG assisted SCFs methods are determined. This study reports the effects of different chemical agents (chelating agent and surfactant) in SG method and the effects of pressure and temperature of HP-HT batch wise reactor system using ethanol as solvent on the phase purity and microstructure of the BCZY powders. Chelating agent (triethylenetetramine, TETA) and surfactant (Brij-97) aided to produce a single perovskite phase of BCZY at calcination temperatures of 1100 °C and 950 °C, respectively. On the other hand, a single perovskite phase of BCZY was obtained via SCFs assisted with sol-gel (SG-SCFs) method. The optimum characteristics of BCZY powder was found in the one prepared at P = 2 MPa and T = 150 °C and 200 °C. Particles of the powders produced by SG and SG-SCFs methods are spherical in-shape. As proven, SG method is able to produce better phase purity and homogenize BCZY powder at lower processing temperature that meets criteria to be used as an electrolyte material.

Electrical Conductivity of Y3+ Doped Ba(Ce,Zr)O3 in Wet N2 Atmosphere Prepared with the Addition of Brij-97

2020 ◽  
Vol 307 ◽  
pp. 160-165
Author(s):  
Nur Syafkeena Mohd Affandi ◽  
Nafisah Osman ◽  
Oskar Hasdinor Hassan
Keyword(s):  
Grain Size ◽  
Calcination Temperature ◽  
Electrochemical Impedance ◽  
Perovskite Phase ◽  
Total Conductivity ◽  
Processing Temperature ◽  
Barium Cerate ◽  
Electrical Measurements ◽  
Ceramic Oxide ◽  
Brij 97

Y-doped barium cerate-zirconate ceramic oxide is proven to be a competent material as an electrolyte with high proton conductivity as well as chemical and mechanical stabilities in carbon dioxide and water vapour atmospheres. This ceramic oxide requires high processing temperature which will results in the increase of particle/grain size. Hence, modification on the synthesis route has been studied in reducing the particle/grain size of the ceramic by lowering the calcination temperature. In this work, BaCe0.54Zr0.36Y0.1O2.95 (BCZY) powder was synthesized with addition of surfactant (Brij-97) through an established modified sol-gel route. Single BCZY perovskite phase was successfully obtained at calcination temperature of 950°C which was lower than our previous study (T=1100°C). The prepared sample was made into pellet by a dry pressing technique with diameter, d=13 mm and thickness, t~2 mm and then subjected to a two-step sintering method prior to morphological and electrical measurements. Impedance measurement was carried out at intermediate temperatures (500-800°C) using an Electrochemical Impedance Spectroscopy (EIS) in wet nitrogen atmosphere. Impedance spectrum was analysed to obtain the behaviour of grain core and grain boundary responses by a fitting procedure using a brick-layer model. Scanning electron microscope (SEM) analysis of fractured pellet revealed that BCZY prepared with the assisted of Brij-97 exhibited dense, homogenous and less agglomerate grain with grain size around 88 nm, which may explain the enhancement in the total conductivity of the BCZY electrolyte.

Dielectric Properties of Mn, Co, and Ni-Doped LaSrFeO3 Films with Different Annealing Atmosphere

2015 ◽  
Vol 740 ◽  
pp. 28-31
Author(s):  
Yang Lu Hou ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Hong Di Xue
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Film Surface ◽  
Annealing Atmosphere ◽  
Single Perovskite Phase ◽  
Gel Technique

Mn, Co, and Ni-doped La0.5Sr0.5FeO3 thin films were prepared by the sol-gel technique with different annesling atmosphere. The structure and dielectric properties of the films were researched by XRD, SEM and Agilent. The study found that LSF-Mn (Co, Ni) films under the argon annealing atmosphere were have optimal dielectric properties. And Mn, Co, Ni elements are integrated into La0.5Sr0.5FeO3 lattices with the single perovskite phase. And uniform grain was distribution on the film surface.

Structure and Dielectric Properties of Mg, Cr-Doped LaSrFeO3 Films

2014 ◽  
Vol 538 ◽  
pp. 11-14
Author(s):  
Yang Lu Hou ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Xin Jin
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Doping Amount ◽  
Single Perovskite Phase ◽  
Pure Perovskite Phase ◽  
Mg Doped

Mg-doped LaFeO3 thin film and Mg, Cr-doped La0.5Sr0.5FeO3 thin films were prepared by the sol-gel method. The change rules of structure and dielectric properties of the films were studied by XRD, SEM, and Agilent. The dielectric properties of La0.5Sr0.5FeO3 and LaFeO3 films were improved by the substitute with Mg and Cr. The doping amount of Mg and Cr for the optimal dielectric properties of La0.5Sr0.5FeO3 films is 45mol%, 25mol%, respectively, and for LaFeO3, the doping amount of Mg is 8mol%. The observed pure perovskite phase of the doped films suggested the dissolution of Mn, Co, and Ni in La0.5Sr0.5FeO3 crystal lattice. Mg and Cr were integrate in the lattice of LaFeO3 and La0.5Sr0.5FeO3, and mineral is single perovskite phase. The surface of the film is smooth, without cracks, surface grain size distribution and had uniform grain size.

Preparation of 0.90Bi0.5Na0.5TiO3-0.10BaTiO3 Ferroelectric Thin Film and its Application in Pyroelectric Energy Harvesting

2012 ◽  
Vol 485 ◽  
pp. 23-26 ◽  
Author(s):  
Xiu Cheng Zheng ◽  
Guang Ping Zheng ◽  
Zheng Lin ◽  
Zhi Yuan Jiang
Keyword(s):  
Thin Film ◽  
Energy Harvesting ◽  
Indium Tin Oxide ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Solution Process ◽  
Precursor Solution ◽  
Single Perovskite Phase ◽  
Ito Glass

Ferroelectric0.90Bi0.5Na0.5TiO3-0.10BaTiO3(0.90BNT-0.10BT) thin film with single perovskite phase is prepared using an improved sol-gel spin coating method onto indium-tin-oxide (ITO) glass substrates. A new solution process is developed for the preparation of precursor solution which is stable in air, presenting a low gelation and trend to the formation of precipitates. The as-prepared thin film is crystallized into single perovskite phase and has good ferroelectric properties. It is remarkable that the thin films show excellent heat-to-electrical energy conversion properties. The results of this work for the first time demonstrate the feasibility of using lead-free BNT-BT films for pyroelectric energy harvesting.

Evolution of Phase Structure and Micro-Morphologies of the La0.7M0.3MnO3 (M=Ca, Sr) Sintered at Different Temperature

2015 ◽  
Vol 1095 ◽  
pp. 402-406
Author(s):  
Shao Qun Jiang ◽  
Gang Wang ◽  
Zong Shu Li ◽  
Ze Hua Wang ◽  
Ze Hua Zhou ◽  
...  
Keyword(s):  
Phase Structure ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Obvious Effect ◽  
Single Perovskite Phase ◽  
Solid State Sintering ◽  
Gel Technique ◽  
Cubic Structure ◽  
Sintering Method

The La0.7M0.3MnO3 (M=Ca, Sr) were synthesized by combining sol-gel technique and solid state sintering method. The evolutions of phase structure and micro-morphologies of the La0.7M0.3MnO3 with final sintering temperature (950-1250°C) were investigated. The results show that the La0.7Ca0.3MnO3 compounds exhibit single perovskite phase with cubic structure and the La0.7Sr0.3MnO3 compounds exhibit single perovskite phase with rhombohedra structure. The final sintering temperature has no obvious effect on the phase structure of La0.7Ca0.3MnO3. However, the density and grain size of La0.7M0.3MnO3 (M=Ca, Sr) increase with the increase of the final sintering temperature. Moreover, the micro-morphologies of La0.7Ca0.3MnO3 are more sensitive to final sintering temperature compared with that of La0.7Sr0.3MnO3. When sintering temperature is no less than 1150°C, the La0.7Ca0.3MnO3 has hardly any pore. After sintering at no less than 1250°C, the La0.7Sr0.3MnO3 becomes dense.

Phase Analysis of Cerate and Zirconate Ceramics Powder Prepared by Supercritical Ethanol Using High Temperature-High Pressure Batch Wise Reactor System

2020 ◽  
Vol 307 ◽  
pp. 171-175
Author(s):  
Nafisah Osman ◽  
Nurul Waheeda Mazlan ◽  
Oskar Hasdinor Hassan ◽  
Wan Zuliana Wan Zulkifli ◽  
Zakiah Mohamed
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Calcination Temperature ◽  
Reaction Medium ◽  
Reactor System ◽  
Synthesis Methods ◽  
Processing Temperature ◽  
Barium Zirconate ◽  
Barium Cerate ◽  
Supercritical Ethanol

OAbstract. One of the approaches that has been done to produce a better performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) is by varying the synthesis methods. This paper focused on the proton conducting electrolyte in particularly barium cerate and barium zirconate system namely BaCe0.9Y0.1O3-δ (BCY) and BaZr0.9Y0.1O3-δ (BZY). Supercritical ethanol processing technique is one of the alternative synthesis routes that able to produce ceramics powder at lower calcination temperature. The samples were synthesized in High-Pressure-High-Temperature (HP-HT) Batch Wise reactor system using ethanol as reaction medium. XRD was used to study the structure of both samples and all the data were refined using Rietveld refinement method by X’pert Highscore software. VESTA software is used to observe the crystal structure for both BCY and BZY samples. Both BCY and BZY have 98.16% and 96.55% purity after being calcined at 700°C and 1100°C, respectively. This study showed that BCY has orthorhombic structure with lattice parameter a=8.76Å, b=6.24Å and c=6.21Å and BZY exhibited cubic structure with a=b=c, and a=4.194Å. It was observed that BCY synthesized by supercritical fluid (SCF) method at reduced calcination temperature exhibited an acceptable value of lattice paramter as compared to other method that used higher processing temperature.

OPTIMIZATION OF PROCESSING TEMPERATURE TO ACHIEVE HIGH QUALITY SOL–GEL-DERIVED PZT THIN FILM

2009 ◽  
Vol 08 (03) ◽  
pp. 299-303 ◽  
Author(s):  
SAJJAD DEHGHANI ◽  
ABDOLGHAFAR BARZEGAR ◽  
MOHAMMAD HOSSEIN SHEIKHI
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Morphological Properties ◽  
Processing Temperature ◽  
High Quality ◽  
Pzt Thin Films ◽  
Polarization Voltage ◽  
Si Substrates

Ferroelectric PbZr 1-x Ti x O 3 (PZT) thin films have been extensively investigated because of their excellent piezoelectric, pyroelectric, ferroelectric, and dielectric properties. Sol–gel synthesis and spin-coating are popular routes to the formation of high quality, dense, and crack-free thin films. In this work, high quality, crack-free PZT thin films have been prepared by sol–gel method via spin-coating on Pt/Ti/SiO2/Si substrate by different temperature processings. The crystallographic and morphological properties of the films have been analyzed by X-ray diffraction and scanning electron microscopy. The electrical properties of thin films including the permittivity, loss tangent, and polarization–voltage hysteresis loop were measured and compared for different films. Finally, by optimizing temperature processing, highly textured and high quality films of PZT with perovskite phase were obtained on Pt/Ti/SiO2/Si substrates.

Phase-formation kinetics of xerogel and electrical properties of sol-gel-derived BaxSr1−xTiO3 thin films

1997 ◽  
Vol 12 (5) ◽  
pp. 1327-1334 ◽  
Author(s):  
Soo-Ik Jang ◽  
Byung-Cheul Choi ◽  
Hyun M. Jang
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Life Time ◽  
Titanium Isopropoxide ◽  
Hydrolysis Rate ◽  
Relative Dielectric Permittivity ◽  
Strontium Chloride ◽  
Heating Rates ◽  
Enolic Form

Chemically homogeneous BaxSr1−xTiO3 (BST with x = 0.6) multicomponent sol was synthesized using barium oxide, strontium chloride, and Ti-alkoxide (titanium isopropoxide) as starting materials. Acetylacetone (AcAc) was introduced as a chelating agent to reduce a rapid hydrolysis rate of Ti-alkoxide. Analysis of Fourier transform infrared spectroscopy (FTIR) spectra indicated that the stabilization of BST sols was achieved by the chelation of Ti-alkoxide with the enolic form of AcAc. The effective activation energy associated with the formation of perovskite phase from the xerogel was estimated by the differential thermal analysis (DTA) experiment using various heating rates. It is approximately 400 kJ/mol with the Avrami exponent (reaction order) of n = 1, suggesting that the growth of perovskite BST is diffusion-controlled. The calculated half-life time suggests that the minimum temperature for the crystallization which is practically accessible to a real processing is approximately 600 °C. The BST thin film fabricated on the “Pt(150 nm)/Ti(100 nm)/SiO2(100 nm)/Si” substrate exhibited the relative dielectric permittivity of 310 and can be represented by an equivalent circuit consisting of a resistive component originated from the bulk perovskite grain and a parallel RC component resulting from the presence of the grain boundary.

Synthesis, Structural and Physicochemical Characterization of BaFe1-xAlxO3−δ Oxides

2016 ◽  
Vol 10 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Hanane Fodil ◽  
◽  
Mahmoud Omari ◽  
Keyword(s):  
Electrical Conductivity ◽  
Surface Area ◽  
Sol Gel ◽  
Physicochemical Characterization ◽  
Total Pore Volume ◽  
Chelating Agent ◽  
Powder Size ◽  
X Ray Diffraction ◽  
Calcination Temperatures ◽  
Xrd Techniques

In this study, BaFe1−xAlxO3-δ (0 ≤ x ≤ 0.3) perovskite-type oxides were prepared by sol-gel method using citric acid as chelating agent. The samples were subjected to various calcination temperatures in order to investigate the physicochemical properties of the oxide affected by the parameter. Thermogravimetric analysis, Fourier transform infrared spectroscopy and X-ray diffraction (XRD) techniques are used to explore precursor decomposition and to establish adequate calcination temperature for the preparation of the nano-powders. The studied compounds have hexagonal crystal structure at the temperature of 1123 K. The samples obtained after calcination at 1123 K were characterized by XRD, Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy, powder size distribution and electrical conductivity. The microstructure and morphology of the compounds show that the particles are nearly spherical in shape and are partially agglomerated. The highest surface area and total pore volume are achieved for BaFe0.8Al0.2O3-δ oxide. Temperature dependence of electrical conductivity shows a semiconducting behavior.

Study on the Electrolyte Material BaCe1-xYxO3-δ’s Raman Spectra and Electrical Properties for Intermediate-Temperature Solid Oxide Fuel Cells

2011 ◽  
Vol 233-235 ◽  
pp. 2419-2423
Author(s):  
Jin Xia Wang ◽  
Jia Wen Jian ◽  
Yuan Yuan Gu
Keyword(s):  
Oxygen Vacancy ◽  
Solid Oxide Fuel Cells ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Solid Oxide ◽  
Crystal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Perovskite Phase ◽  
The Relationship

In this paper we used sol-gel method for synthesizing Y3+-doped BaCeO3 solid electrolyte BaCe1-xYxO3-δ(x=0.10, 0.15, 0.20, 0.25, 0.30). The samples crystallized in a single perovskite phase by X-ray diffraction analysis after sintering at 1450°C in air for 10h; Raman spectrum measurements indicated that the increasing of Y3+ doped content increased the crystal symmetry and increased the oxygen vacancy content for the samples, all Y3+ ions were doped into the Ce-sites; The electric conductivities of the samples increased with Y content and reach a maximum at x=0.25, then decreased. The relationship between proton conductivity and Y dopant was closely related with oxygen vacancy content, crystal symmetry and the forming of defect association.

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