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.

Effects of Sr Doping Content on the Structure and Morphologies of La0.7SrxCa0.3-xMnO3

2015 ◽  
Vol 1120-1121 ◽  
pp. 507-511
Author(s):  
Gang Wang ◽  
Shao Qun Jiang ◽  
Qi Zhang ◽  
Meng Wu ◽  
Ze Hua Wang ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Doping Content ◽  
X Ray Diffraction ◽  
Structure Transition ◽  
X Ray ◽  
Single Perovskite Phase ◽  
Dense Microstructure ◽  
Cubic Structure

The La0.7SrxCa0.3-xMnO3 (x=0, 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3) were prepared by combining sol-gel method and high temperature sintering. The effects of Sr doping content on the structure and morphologies of the La0.7SrxCa0.3-xMnO3 finally sintered at 1050°C/1250°C were investigated based on the analyses of X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results show that the La0.7SrxCa0.3-xMnO3 exhibit single perovskite phase and the change of Sr doping content can result in phase structure transition. The La0.7SrxCa0.3-xMnO3 samples are rhombohedra structure in the range of 0.15≤x≤0.3. When x is no more than 0.1, the La0.7SrxCa0.3-xMnO3 samples sintered at 1050°C present distorted cubic structure. The microstructure of La0.7SrxCa0.3-xMnO3 sintered at 1050°C for 5h becomes more and more looser and its grains tend to refinement with the increase of Sr doping content when x is no less than 0.05. Increasing the final sintering temperature can improve the density and promote the grain growth of La0.7SrxCa0.3-xMnO3. In order to gain a dense microstructure, the final sintering temperature of La0.7SrxCa0.3-xMnO3 should be higher than 1050°C and should be suitably increased with the increase of Sr doping content.

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.

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.

Study on the Properties of Al-Al2O3 Composite Using Synthesized Alumina from Sol Gel Technique

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Hasmaliza Mohamad ◽  
Hanisah Abdul Rani
Keyword(s):  
Metal Matrix ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Comparison Study ◽  
Commercial Alumina ◽  
Al2o3 Composite ◽  
Alumina Particles ◽  
Gel Technique ◽  
Ideal Method ◽  
The Ideal

Alumina reinforced aluminum is one of metal matrix composite (MMC) systems that can maintain its properties although at high temperature. Among various processes to produce MMC, powder metallurgy is the best method because of its efficiency dispersion of fine alumina particles. In this study, alumina powders were synthesized through sol gel method which is known as one of the ideal method to produce good properties of powders. The performances of synthesized alumina powders were then observed through the fabrication of composite. The percentage of alumina (0wt%, 10wt%, 20wt% and 30wt %) and sintering temperature (500°C and 550°C) were varied in order to observed their effects on the produced composite. Result shows that by increasing the percentage of alumina and sintering temperature, mechanical properties were increased where 30wt% alumina and 550°C sintering temperature give the optimum results. Comparison study by using 30wt% alumina and 550°C sintering temperature on the composite using synthesize and commercial alumina shows similar/comparable properties of composite.

PHASE STRUCTURE, PIEZOELECTRIC AND MULTIFERRIOC BEHAVIOR OF (K0.48Na0.52)NbO3-Co2O3 PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 04 (03) ◽  
pp. 225-229 ◽  
Author(s):  
WENJUAN WU ◽  
DINGQUAN XIAO ◽  
JIAGANG WU ◽  
JING LI ◽  
JIANGUO ZHU
Keyword(s):  
Room Temperature ◽  
Sintering Temperature ◽  
Magnetic Behavior ◽  
Orthorhombic Phase ◽  
Piezoelectric Ceramics ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Solid State Sintering ◽  
Sintering Method

( K 0.48 Na 0.52) NbO 3-x% Co 2 O 3 (x = 0, 0.03 and 0.05) (KNN-x% Co2O3 ) lead-free piezoelectric ceramics were prepared by the conventional solid-state sintering method. An orthorhombic phase was observed for all KNN-x% Co2O3 ceramics at room temperature, and two phase transitions were confirmed by the high temperature X-ray diffraction and the temperature dependence of the dielectric constant. The Co2O3 greatly improves the density and decreases the sintering temperature of KNN ceramics. The KNN-0.05 mol%Co2O3 ceramic exhibits good properties (d33 = 120 pC/N , k p = 0.41, Q m = 213 and T c = 407°C) and a good age stability. The multiferroic behavior was also observed at room temperature for the KNN-0.05 mol%Co2O3 ceramic, as confirmed by P–E loops and magnetic behavior.

Structure and Dielectric Properties of Zn Doped PST Thin Films Prepared by Sol-Gel Method

2007 ◽  
Vol 336-338 ◽  
pp. 283-286 ◽  
Author(s):  
Zan Zheng ◽  
Xiao Ting Li ◽  
Gao Rong Han ◽  
Wen Jian Weng ◽  
Pi Yi Du
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Phase Structure ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Dip Coating ◽  
In Doping ◽  
Ito Glass ◽  
Coating Method ◽  
Dip Coating Method

(PbySr1-y)ZnxTi1-xO3-x thin films were prepared on ITO/glass substrate by sol–gel process using dip-coating method. The phase structure, morphology, and dielectric properties of thin films were investigated by XRD, SEM and impedance analyzer, respectively. The perovskite phase structure was exhibited in the Zn-doped PST thin films. The formation ability of the thin films of the perovskite phase and its grain size decreased with the increase in doping Zn. The dielectric constant of the thin film was influenced by oxygen vacancies which could be controlled by Zn doping.

scholarly journals Enhancement of Photocatalytic Activity by Mg2+ Doped Ceria Quantum Dots

2017 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Quantum Dot ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Cubic Structure

The pure and Mg2+ doped CeO2 quantum dot were synthesized by sol-gel technique. The prepared quantum dots were characterized using X-ray diffraction pattern (XRD), Scanning electron microscope (SEM-EDX). The XRD results show cubic structure of the CeO2 quantum dots. The crystalline size (D), microstrain (ε), dislocation density (δ) and lattice parameter (α) were calculated and analyzed. SEM-EDX analysis shows the morphology and the presence of elements. The photocatalytic activity of the synthesized quantum dot was evaluated based on the photodegradation of methylene blue (MB) by UV-Vis spectrometry.

scholarly journals Characteristics of unsupported alumina membrane prepared using sol-gel technique

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
M.R. Othman, ◽  
A.L. Ahmad ◽  
H. Mukhtar
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Alumina Membrane ◽  
Porous Support ◽  
Porosity Level ◽  
Gel Layer ◽  
Gel Technique ◽  
Coating Time

A laboratory scale alumina membrane was prepared using sol-gel technique. Results from the experiment demonstrate that the addition of PVA is important for viscosity adjustment to determine the appropriate coating time if the membrane is required for coating on the porous support. The effects of varying PVA content  and sintering temperature on the characteristics of the sintered membrane are discussed. In this work, a 2 volume % of PVA solution containing 4g of PVA in lOOml of water was discovered to be adequate to achieve appropriate porosity level and avoid cracks in the gel layer. It was also discovered that the sol viscosity essentially increased as the PVA addition was increased. On the contrary, the coating time decreased as PVA content in the sol was increased. Generally, the pore size of the membrane increased with the increase in PVA addition. The density of the membrane increased with increase in sintering temperature. The porosity level however, decreased as the temperature was increased. The pore size became greater and pore size distribution wider at higher sintering temperatures.

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