Preparation of Ultra–Fine La3NbO7 Powder by Solid State Reaction

2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granular Particle ◽  
Fine Particle Size ◽  
Ultra Fine Particle ◽  
Different Temperatures

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.

Luminescence Properties of Self-Activated M3(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method

2016 ◽  
Vol 16 (4) ◽  
pp. 3684-3689 ◽  
Author(s):  
Xin Min ◽  
Zhaohui Huang ◽  
Minghao Fang ◽  
Yan’gai Liu ◽  
Chao Tang ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Uv Light ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Reaction Method ◽  
X Ray ◽  
Yield Decrease

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).

Synthesis, Phase Formation and Characterization of Co4Nb2O9 Powders Synthesized by Solid-State Reaction

2008 ◽  
Vol 55-57 ◽  
pp. 873-876 ◽  
Author(s):  
N. Chaiyo ◽  
R. Muanghlua ◽  
A. Ruangphanit ◽  
Wanwilai C. Vittayakorn ◽  
Naratip Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Dwell Time ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Techniques ◽  
Scanning Electron

A corundum-type structure of cobalt niobate (Co4Nb2O9) has been synthesized by a solid-state reaction. The formation of the Co4Nb2O9 phase in the calcined powders was investigated as a function of calcination conditions by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. Morphology and particle size have been determined by scanning electron microscopy (SEM). It was found that the minor phases of unreacted Co3O4 tend to form together with the columbite CoNb2O6 phase at a low calcination temperature and short dwell time. It seems that the single-phase of Co4Nb2O9 in a corundum phase can be obtained successfully at the calcination conditions of 900°C for 60 min, with heating/cooling rates of 20°C /min.

scholarly journals Synthesis of Vanadium (III) Doped Anatase TiO2 by Solid State Reaction Method

ALCHEMY ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Nur Aini ◽  
Rachamawati Ningsih
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Solid State Reaction ◽  
Single Phase ◽  
Diffuse Reflectance Spectroscopy ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Vanadium Doping

Anatase of Titanium dioxide (TiO<sub>2</sub>)  was doped with vanadium ions (V<sup>3+</sup>), at doping levels ranging from 0.3, 0.5 to 0.7 atomic percentage in order to increase its photocatalytic activity under visible light irradiation. Vanadium doped TiO<sub>2</sub> was synthesized by solid state reaction method. Its physicochemical properties characterized by powder X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy (DRS). Doping with V(III) resulted in a single phase structure of anatase TiO<sub>2</sub> with nanosize crystal ranging from 53.06 to 59.59 nm. Vanadium doping also resulted in a red-shift of the photophysical response of TiO<sub>2</sub> that was reflected in an extended absorption in the visible light between 400 and 700 nm.

VARIATION OF Tc IN SINGLE PHASE Bi2Sr2Ca1Cu2O8−x SYSTEM

1991 ◽  
Vol 05 (24n25) ◽  
pp. 1645-1653
Author(s):  
M. NASIR KHAN ◽  
F.A. KHWAJA ◽  
RAANA FARID
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Electron Density ◽  
Solid State Reaction ◽  
Single Phase ◽  
High Temperature Superconductor ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
X Ray

The variation of Tc in a single-phase high temperature superconductor Bi 2 Sr 2 Ca 1 Cu 2 O 8−x is studied using techniques like X-ray diffraction, magnetic and electric measurements. The samples of Bi-Sr-Ca-Cu-O (with nominal composition 2212) are synthesized by solid state reaction using appropriate amounts of Bi 2 O 3, SrCO 3, CaCO 3 and CuO powders. The Tc is found to vary from 92 K to 115 K in the quenched samples. These changes in the value of Tc have been related to the changes in the inter-layer spacing. It is concluded that an increase in the electron density due to shortening of the inter-layer increases the attractive interaction between pairs and is thus responsible for the high Tc in these superconductors.

scholarly journals Effect of Zr addition on structure and electrical properties of SmFeO3 prepared by solid state reaction method

2017 ◽  
Vol 11 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Abdalla Abdalla ◽  
Shahzad Hossain ◽  
Pg. Petra ◽  
Abul Azad
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Zr Addition ◽  
Pbnm Space Group

Series of Sm1-xFe1-3xZr3xO3 (SFZO, where x = 0.0, 0.01, 0.02, 0.033, 0.05, 0.1 and 0.15), was synthesised by the solid state reaction method and sintered at 1500?C in air. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structure of the materials. The XRD results indicated that the pure SmFeO3 and Sm0.99Fe0.97Zr0.03O3 samples are single phase materials with an orthorhombic symmetry and Pbnm space group. The increase of Zr content (x ? 0.02) causes a phase change from single to twophase system with orthorhombic (Pbnm) and fluorite symmetry (Fm?3m). The microstructural analyses showed that the Zr4+ doping resulted in an increase of porosity in the sintered SFZO compared to SmFeO3 sample. The direct current (DC) electrical conductivity at 850?C in air was found to be 0.045 S/cm and 0.007 S/cm for Sm0.99Fe0.97Zr0.03O3 and SmFeO3, respectively, showing a significant enhancement compared to the pure SmFeO3.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

Thermal enhancement of 2H11/2→4I15/2 up-conversion luminescence of Er3+ doped K2Yb(PO4)(MoO4) phosphors

2021 ◽  
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Reaction Method ◽  
X Ray ◽  
Thermal Enhancement

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...

Changes in Crystallite Size of Tricalcium Silicate during the Laboratory Grinding

2021 ◽  
Vol 321 ◽  
pp. 23-27
Author(s):  
Simona Ravaszová ◽  
Karel Dvořák
Keyword(s):  
Solid State ◽  
Crystallite Size ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Tricalcium Silicate ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Grinding Time

The paper is focused on one of the most important component of Portland clinker-on the tricalcium silicate. The study reported in this article is focuses on the changes in crystallite size of synthetic tricalcium silicate obtained using solid state reaction method. Crystallite size changes are monitored during the grinding in three types of laboratory mills in two different conditions. Changing in crystallite size at various grinding time up to 120 minutes are studied with the aid of X-ray diffraction and using the Scherrer equation. It has been found that the most efficient laboratory mill in terms of speed and fineness of the material was the planetary mill.

Karakterisasi Kekristalan dan Konstanta Dielektrik Barium Stronsium Titanat (BaxSr1-XTiO3) dengan Variasi Komposisi Barium Dan Stronsium Yang Dibuat Menggunakan Metode Solid State Reaction

2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Alpi Zaidah
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Holding Time ◽  
X Ray Diffraction ◽  
X Ray

Pembuatan sampel barium stronsium titanat (BaxSr1-xTiO3) telah dilakukan dengan metode solid state reaction. Variasi komposisi mol Ba(x) untuk pembuatan sampel adalah x=0,4;0,3 dan 0,2. Sampel di-sintering pada suhu 1100oC dengan holding time 2 jam. Karakterisasi sampel dilakukan menggunakan peralatan X-Ray Diffraction (XRD) untuk mengetahui tingkat kekristalan dan ukuran kristal dari sampel. Sedangkan untuk mengetahui besarnya konstanta dielektrik menggunakan RLC-Meter.  Berdasarkan analisa dengan software GSAS, parameter kisi BaxSr1-xTiO3 yang sintering pada suhu 1100°C untuk x=0,4 adalah a=b=c=3,947 nm. Parameter kisi a=b=c=3,947 nm untuk x=0,3, dan parameter kisi a=b=c=3,939 nm untuk x=0,2. Nilai parameter kisi a=b=c menunjukkan struktur kristal berbentuk kubik. Ukuran kristal berturut-turut untuk x=0,4;0,3 dan 0,2 adalah 65 nm, 66 nm dan 69 nm. Ukuran kristal semakin besar seiring dengan meningkatnya penambahan Sr. Pengukuran konstanta dielektrik (K) dilakukan pada rentang frekuensi 1 kHz. Nilai K sampel dengan x=0,4;0,3 dan 0,2 masing-masing sebesar 265, 277 dan 307.

scholarly journals Impact of Lithium Composition on Structural, Electronic and Optical Properties of Lithium Cobaltite Prepared by Solid-state Reaction

2014 ◽  
Vol 6 (2) ◽  
pp. 217-231 ◽  
Author(s):  
F. Khatun ◽  
M. A. Gafur ◽  
M. S. Ali ◽  
M. S. Islam ◽  
M. A. R. Sarker
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Ionic Conductivity ◽  
Cathode Material ◽  
Solid State Reaction ◽  
Layered Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electronic And Optical Properties ◽  
Lithium Cobaltite

The lithium-cobalt oxide LixCoO2 is a promising candidate as highly active cathode material of lithium ion rechargeable batteries. The crystalline-layered lithium cobaltite has attracted increased attention due to recent discoveries of some extraordinary properties such as unconventional transport and magnetic properties. Due to layered crystal structure, Li contents (x) in LixCoO2 might play an important role on its interesting properties. LiCoO2 crystalline cathode material was prepared by using solid-state reaction synthesis, and then LixCoO2 (x<1) has been synthesized by deintercalation of produced single-phase powders. Structure and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), Infrared spectroscopy, Impedance analyzer etc. The influence of lithium composition (x) on structural, electronic and optical properties of lithium cobaltite was studied. Temperature dependent electrical resistivity was measured using four-probe technique. While LixCoO2 with x = 0.9 is a semiconductor, the highly Li-deficient phase (0.75 ? x ? 0.5) exhibits metallic conductivity. The ionic conductivity of LixCoO2 (x = 0.5 – 1.15) was measured using impedance spectroscopy and maximum conductivity of Li0.5CoO2 was found to be 6.5×10-6 S/cm at 273 K. The properties that are important for applications, such as ionic conductivity, charge capacity, and optical absorption are observed to increase with Li deficiency. Keywords: Calcination; Characterization; Inorganic compounds; Solid-State reaction; X-ray diffraction. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v6i2.17900 J. Sci. Res. 6 (2), 217-231 (2014)  

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