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.

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.

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.

Lower crystallization temperature of sol-gel PbTiO3 on Ti/Pt-coated substrates

1999 ◽  
Vol 14 (6) ◽  
pp. 2369-2372 ◽  
Author(s):  
R. E. Avila ◽  
T. P. Velilla ◽  
P. J. Retuert
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Range Analysis ◽  
X Ray

PbTiO3 (PT) thin films have been deposited by sol-gel on Pt/Si, SiO2/Si, Pt/Ti/SiO2/Si, and Ti/Pt/Ti/SiO2/Si and annealed for 45 min in the 400–670 °C range. Analysis by x-ray diffraction (XRD) and spectroscopic ellipsometry shows that the Ti overlayer promotes early crystallization in the tetragonal perovskite phase, reducing the presence of a second phase, tentatively identified as pyrochlore, starting by 450 %C. The refractive index and extinction coefficient (n, k) of the PT film increase rapidly with the sintering temperature in the range of 450–570 °C and saturate by 570 °C to values of n varying from 2.4 to 2.9, and k from 0.03 to 0.3, over the 1.65–2.95 eV range. Most of the increase of n is related to thin film densification.

Sintering AlN Ceramics Below 1500°C with MgO-CaO-Al2O3-SiO2 Glass Addition

2007 ◽  
Vol 336-338 ◽  
pp. 1868-1871 ◽  
Author(s):  
Cheng Fu Yang ◽  
Chien Min Cheng ◽  
Ho Hua Chung ◽  
Chao Chin Chan
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Dielectric Characteristics ◽  
Sintering Aid ◽  
Glass Addition ◽  
X Ray ◽  
Crystal Phases ◽  
Diffraction Patterns ◽  
Scanning Electron

5~15 wt% MgO-CaO-Al2O3-SiO2 (MCAS, fabricated by sol-gel method) glass is used as the sintering aid of AlN ceramics. The sintering is proceeded from 1350oC~1550oC, scanning electron microscope is used to observe the sintered morphologies and X-ray diffraction pattern are used to confirm the crystal structures. From the SEM observations, as 10wt% and 15wt% MCAS is added, AlN ceramics can be densified at 1500oC and 1450oC, which are much lower than the before studies were. From the X-ray diffraction patterns, the crystal phases of MCAS-AlN ceramics are AlN, Al2O3, and cordierite phases. In this study, the dielectric characteristics of MCAS-AlN ceramics are also developed as a function of MCAS content and sintering temperature.

X-ray diffraction analysis for thin films of PbTiO3-La2/3TiO3 prepared by the sol-gel method

1994 ◽  
Vol 9 (8) ◽  
pp. 2133-2137 ◽  
Author(s):  
Hideki Yoshioka
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Diffraction Method ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coating Methods ◽  
Diffraction Patterns ◽  
System 1

Thin films in the system (1 - x) PbTiO3−xLa2/3TiO3 were prepared by the sol-gel and dip-coating methods. Phases deposited in the films and the lattice parameters as a function of the composition were investigated by the x-ray diffraction method. The solid solutions with a perovskite structure were formed as a single phase with x up to 0.9. For the composition of x = 1.0, metastable La-Ti-O perovskite phase with a small amount of the impurity phase, La2Ti2O7, was obtained. Simulation of x-ray diffraction patterns based on the defect structure model shows that the structure of the La-Ti-O perovskite phase includes randomly distributed cation vacancies at the A-site, namely (La2/3□1/3)TiO3.

Production of Porous Cordierite through Sol-Gel Polymeric Sponge Method

2012 ◽  
Vol 620 ◽  
pp. 127-131 ◽  
Author(s):  
Mohamad Hasmaliza ◽  
M. Siti Naqiah ◽  
R.J. Shafinaz ◽  
Ibrahim Norfadhilah
Keyword(s):  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
High Melting ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Melting Temperature ◽  
Sem Micrograph ◽  
Porous Cordierite ◽  
Scanning Electron

Cordierite (2MgO.2Al2O3.5SiO2) is widely used in high temperature applications due to its high melting temperature and high resistance to thermal shock, chemical and corrosion. In this study, porous cordierite was synthesized using sol-gel method followed by replication of polymeric sponge method. Three different sintering temperatures were studied (1200°C, 1300°C and 1400°C to determine the crucial temperatures meant for pure cordierite phase. The effect of different temperature on the pore size, density and porosity were also studied. Produced porous cordierite was then analyzed using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results showed that pure cordierite phase was obtained at 1300°C. SEM micrograph shows that with increasing sintering temperature, the pore size decreased and sample sintered at 1300°C has pore size ranging from 61-126μm.

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 The Synthesis and Characterizations of CeY0.15Er0.05O2 Nanocrystal

2021 ◽  
Vol 22 (2) ◽  
pp. 341-344
Author(s):  
Handan Özlü Torun
Keyword(s):  
Crystal Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Impedance Analysis ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Species ◽  
Unit Cell Size ◽  
Structure Properties

CeY0.15Er0.05O2 nanocrystal powders prepared via sol-gel method. Phases identification have been made X-ray diffraction, SEM-EDX, FTIR, thermal and impedance analysis. XRD data show that all powders were obtained with cubic fluorite structure. With the increase of sintering temperature, the unit cell size decreased and the crystal size increased. The particle size was found to be in the range of 150 to 270 nm. It was found that the nitrates and organic species seen in the FTIR results. It was observed that organic species disappeared at sintering temperatures selected according to thermal analysis results. Impedance measurements of the pelletized sample were made. Although the crystal structure properties were good, it was found that the conductivity values were low.

Sinterbility of (Bi4-xLax)Ti3O12 Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 841-844 ◽  
Author(s):  
Pasinee Siriprapa ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Grain Orientation ◽  
Sintering Temperature ◽  
Orthorhombic Phase ◽  
Preferred Orientation ◽  
Doping Content ◽  
X Ray Diffraction ◽  
Microstructural Investigation ◽  
X Ray ◽  
Lanthanum Titanate ◽  
Diffraction Patterns

This research studied the effects of sintering temperature and La3+ doping content on phase, microstructure and densification of bismuth lanthanum titanate (Bi4-xLaxTi3O12; BLT) ceramics when x = 0, 0.25, 0.5, 0.75 and 1.0, respectively. The BLT powders were prepared using a mixed-oxide method. The mixtures were calcined at 750°C for 4 h before being pressed and sintered at 1000-1150°C for 4 h. The result of phase analysis by X–ray diffraction (XRD) indicated the existence of orthorhombic phase for all sintering temperatures. The XRD peak intensities of the ceramics showed preferred orientation of a particular set of {00l}-type planes. The ceramics mainly composed of plate-like grains. Increasing the sintering temperature increased grain size and increased preferred grain orientation. The present of La3+ in BLT ceramics reduced preferred orientation especially at higher sintering temperature. Results of microstructural investigation agreed well with X-ray diffraction patterns.

Synthesis of Nano-Sized SrTiO3 Photocatalyst by Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Zhao ◽  
Jian Jun Yao ◽  
Jing Ya ◽  
Lei E ◽  
Zhi Feng Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Complexing Agent ◽  
Strontium Nitrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Gel Processing

A sol-gel processing technology was employed to synthesize fine SrTiO3 powder by using strontium nitrate (Sr(NO3)2) , butyl titanate (Ti(OC4H9)4) as precursors, citric acid (C6H8O6) as complexing agent and (ethylene) glycol (C2H6O2) as stabilizer. Prepared the precursors in liquid phase and then calcined the precursors to achieve nano-sized SrTiO3 powders. The microstructure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), Scan Electron Microscopy (SEM), and the photocatalytic activity was studied. The results showed that all the SrTiO3 particles were identified as perovskite phase. The pH values, the content of the acetic acid, the heat treat temperature play important roles on the synthesis of the SrTiO3 photocatalyst. When the pH=1, n(Sr(NO3)2 ) : n(Ti(OC4H9)4) = 1 : 1, n(Sr(NO3)2 ) : n(C6H8O6)=1:1.7, the product has better rate of photodegradation for the Methylene Blue under the ultraviolet condition.

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