Effect of NH4Cl Flux on Structural and Luminescent Properties of CaS: Eu2+ Phosphors

2014 ◽  
Vol 989-994 ◽  
pp. 755-758
Author(s):  
Yun Jie Zhang ◽  
Jie Zhao ◽  
Da Jian Wang ◽  
Jian Ma
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Raw Materials ◽  
Luminescent Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Structure Morphology ◽  
Scanning Electron

CaS:Eu2+phosphors were prepared by two steps method at a relatively low temperature (1050°C) using NH4Cl as a flux. The influences of NH4Cl flux concentrations on the crystal structure, morphology and photoluminescent properties of CaS:Eu2+phosphors were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL), respectively. XRD analysis shows that when the raw materials added with the NH4Cl flux, the crystal structure was not changed .The SEM images indicate that increase of the NH4Cl flux enlarged the grain size of the phosphor particles. The luminescence intensity of CaS:Eu2+was enhanced with adding NH4Cl flux and up to the maximum emission intensity when the addition of NH4Cl flux is 1wt%.

EFFECT OF EXCESS BISMUTH ON THE SYNTHESIS OF BISMUTH SILICATE (Bi4Si3O12) POLYCRYSTALS

2009 ◽  
Vol 23 (08) ◽  
pp. 2093-2099 ◽  
Author(s):  
J. KAEWKHAO ◽  
N. UDOMKAN ◽  
W. CHEWPRADITKUL ◽  
P. LIMSUWAN
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Electron Microscope ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Bismuth Silicate ◽  
X Ray ◽  
Structure And Morphology ◽  
Crystallization Morphology ◽  
Scanning Electron

In this study, the effect of bismuth content on the crystal structure and morphology of bismuth silicate ( BSO:Bi 4 Si 3 O 12) polycrystals were investigated with X-ray diffraction (XRD) analysis and scanning electron microscope (SEM). BSO materials have been successfully prepared by the solid-state reaction. The BSO phase was crystallized at 950°C for 12 h. In summary, 10% of excess bismuth was found to be the optimum composition with respect to crystallization, morphology, and grain size.

Study on the Properties of Doped La in BaBi4Ti4O15 Ceramic

2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sintering Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lanthanum Content ◽  
Scanning Electron

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.

The Effect of Water Content on the Formation of TiO2 Nanotubes in Ethylene Glycol

2010 ◽  
Vol 173 ◽  
pp. 102-105 ◽  
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan
Keyword(s):  
Crystal Structure ◽  
Aspect Ratio ◽  
Ethylene Glycol ◽  
Water Content ◽  
Anatase Phase ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Degradation Of Methyl Orange ◽  
Scanning Electron

In this paper, anodization of Ti foil was carried out in ethylene glycol (EG) containing 5 wt% NH4F solution and 0 to 1.5 wt% of water at 50 V for 60 min. The pH of the bath was kept constant at ~pH7. The crystal structure was studied by X-Ray Diffraction (XRD) analysis, and the morphology was observed via field emission scanning electron microscopy (FESEM). TiO2 nanotube with aspect ratio of 100 was obtained in EG containing less than 1wt % water. The nanotubes wall was very smooth. Increasing the water content > 1wt % results in short nanotubes of approximately 6.2μm with aspect ratio of 62. As anodized, nanotubes were amorphous and annealed at 400 °C promote 100 % anatase phase. Photocatalytic activity of the nanotubes produced at different water content was also evaluated by the degradation of methyl orange and the detail of the observation was discussed thoroughly in this paper.

Luminescent Properties of Ca1-xBaxSnO3: Eu3+, Dy3+ Composites Prepared by Coprecipitation

2014 ◽  
Vol 989-994 ◽  
pp. 383-386
Author(s):  
Li Min Dong ◽  
Fei Lv ◽  
Qin Li ◽  
Zhi Dong Han ◽  
Xian You Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluorescence Spectroscopy ◽  
Emission Intensity ◽  
Luminescent Properties ◽  
Emission Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Scanning Electron

A series of Eu3+, Dy3+ actived Ca1-xBaxSnO3 phosphors were synthesized by coprecipitation method. The structure, morphology and fluorescence property of phosphors were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. SEM results showed that the as-prepared phosphors are smooth and uniform with the cubic morphology. The incorporation of a small amount of Ba to CaBaSnO3 improved the emission characteristics. Fluorescence spectrum showed the emission intensity is the best with the incorporation of Ba2+ (x = 0.3), when calcination temperature is 900°C.

Insight into the Structural, Electrical, and Magnetic Properties of Al-Substituted BiFeO3 Synthesised by the Sol–Gel Method

2020 ◽  
Vol 75 (3) ◽  
pp. 249-256
Author(s):  
Mukhtar Ahmad ◽  
Rizwan Ali ◽  
Atiq ur Rehman ◽  
Akbar Ali ◽  
Ishrat Sultana ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Sol Gel ◽  
Random Access ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Auto Combustion ◽  
Ferroelectric Random Access Memories

AbstractMultiferroics with chemical formula BiAlxFe1−xO3 (x = 0, 0.1, 0.2, and 0.3) and substituted by Al are synthesised using sol–gel auto-combustion. The materials are sintered at 500 °C for 5 h. In the ongoing study, the crystal structure of BiAlxFe1−xO3 was investigated by X-ray diffraction. After confirming the rhombohedral single-phase crystal structure, various characterisation techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping images, electrical properties, Fourier transform infrared spectroscopy, and vibrating sample magnetometry (VSM), were used to investigate the synthesised samples. The grain size estimated from SEM images decreased as Al contents increased. Elemental composition was confirmed by EDX spectra. Direct current electrical resistivity increased whereas drift mobility decreased with increasing Al contents. The VSM results of Al-doped BiFeO3 (BFO) demonstrate that BFO crystals with size >60 nm show anti-ferromagnetic behaviour, which is evident in the present study. The increase in Al doping results in an increase in coercivity, as grain size and coercivity are inversely related with each other. This is because of the replacement of Fe3+ by Al3+ ions, which weakens the sub-lattice interactions. It has been observed that BFO materials with such parameters are favourable for ferroelectric random access memories where data can be written electrically and read magnetically.

Synthesis of Zeolite X from Bentonite via Hydrothermal Method

2020 ◽  
Vol 990 ◽  
pp. 144-148
Author(s):  
Suphada Srilai ◽  
Worapak Tanwongwal ◽  
Kobchai Onpecth ◽  
Thanapat Wongkitikun ◽  
Kollayut Panpiemrasda ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Method ◽  
The Other ◽  
X Ray Diffraction ◽  
Zeolite X ◽  
Sem Images ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

Zeolite X were successfully synthesized from bentonite from Lopburi province, in Thailand using the two-step of hydrothermal method under optimum condition without calcination. The first step of hydrothermal were obtained at 200 °C for 3 h to remove unreacted impurity minerals such as quartz and muscovite. The secondary step of hydrothermal were obtained at 90 °C for 120 h for synthesis of zeolite X. The characterization of zeolite X were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), and infrared spectroscopy (FT-IR), respectively. The crystal structure of product was determined as zeolite X by XRD. The morphology of SEM images for zeolite X is octahedral shape. FTIR spectra are in accordance with the other characterization results.

scholarly journals Influence of type of precursors on the sol-gel synthesis of the LaCoO3 nanoparticles

2014 ◽  
Vol 22 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Nicoleta Cornei ◽  
Simona Feraru ◽  
Ion Bulimestru ◽  
Andrei Victor Sandu ◽  
Carmen Mita
Keyword(s):  
Crystal Structure ◽  
Sol Gel ◽  
Chelating Agent ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Perovskite Type ◽  
Type Crystal ◽  
Scanning Electron

Abstract Perovskite-type LaCoO3 was prepared by sol-gel method using nitrates / chlorides as precursors and citric acid as chelating agent. Chemical composition was obtained by means of EDX method. The structures of sintered samples were investigated by scanning electron microscopy (SEM), IR and XRD analysis. The results of X-ray diffraction indicated that the LaCoO3nanopowders obtained using nitrate as precursors had a rhombohedral perovskite-type crystal structure (S. G: R-3c), while that obtained using chloride as precursors had a mixture of LaCoO3, LaOCl and Co3O4. The all lanthanum cobaltites exhibit catalytic activity on the decomposition of hydrogen peroxide, ascribed to their higher surface and Co3+ concentration

Morphology of ZnO Controlled by Anion of Simple Zinc Salt

2011 ◽  
Vol 284-286 ◽  
pp. 742-745
Author(s):  
Han Mei Hu ◽  
Chong Hai Deng ◽  
Ke Hua Zhang
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Aqueous Solution ◽  
Raw Materials ◽  
Zinc Salt ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Zinc Salts ◽  
Scanning Electron

In this paper, three kinds of morphologies of ZnO crystals including particle-based lotus-like, hexagonal bipod-like (dumbbell-like) and rod-based chrysanthemum-like microstructures were controllably synthesized by using simple zinc salts (Zn(CH3COO)2·2H2O, ZnSO4·7H2O and Zn(NO3)2·6H2O) and ethanolamine as raw materials in microwave-assisted aqueous solution. The crystal structure, composition and morphology of the as-prepared products are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX), field-emission scanning electron microscopy(FESEM). It was found that anion of zinc salt is a dominative factor in determining the morphology of the obtained ZnO crystals. The possible formation mechanism of ZnO microstructures was simply discussed.

Synthesis and Structural Characterization of La0.8Sr0.2MO3 (M=Mn, Fe, Co and Cr) Solid Ionic Material for Catalyst Application

2016 ◽  
Vol 840 ◽  
pp. 48-51
Author(s):  
Muhammad Nor Azri Aziz ◽  
Johar Banjuraizah ◽  
Shing Fhan Khor ◽  
Zainal Arifin Ahmad
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Raw Materials ◽  
Solid State Reaction Method ◽  
Cold Isostatic Pressing ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Scanning Electron

La0.8Sr0.2MO3+δ, (M=Mn, Fe, Cr, Co) ceramics were prepared by using solid state reaction method. All raw materials were mixed and ground using mortar. Homogenized powders were calcined at 900°C for three hour followed by grounding and uniaxial pressed at 100MPa. Compacted pellets were further pressed using cold isostatic pressing machine at 2600kg/m.s and sintered at 1300°C with heating rate 5°C/min for 4 hour. Crystal structure and phase transformation of sintered samples were obtained using X-ray diffraction. Density and porosity are measured by using Archimedes principle. The morphology of sintered samples is observed using scanning electron microscopy, while elemental analysis using the EDX.

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

Sign in / Sign up

Export Citation Format

Share Document