scholarly journals Effects of Varying Alx Moles on the Structure and Luminescence Properties of ZnAlxO1.5x + 1:0.1% Tb3+ Nano Phosphor Prepared using Citrate sol-gel Method

2021 ◽  
Author(s):  
V Maphiri ◽  
L Melato ◽  
Mhlongo ◽  
TT Hlatshwayo ◽  
TE Motaung ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Single Phase ◽  
Sol Gel ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Nano Phosphor ◽  
Scanning Electron

Abstract Un-doped and ZnAlxO(1.5x + 1):0.1% Tb3+ (ZAOT) nano-powders were synthesized via citrate sol-gel method. The Alx moles were varied in the range of 0.25 ≤ x ≤ 5.0. The X-ray powder diffraction (XRD) data revealed that for the x < 1.5, the prepared samples crystal structure consists of mixed phases of the cubic ZnAl2O4 and hexagonal ZnO phases, while for the x ≥ 1.5 the structure consists of single phase of cubic ZnAl2O4. This was confirmed by the Raman and Fourier-Transform Infrared (FTIR) vibrational spectroscopy. Scanning electron microscopy (SEM) showed that varying Alx moles influences the morphology while Transmission electron microscopy (TEM) shows the dual morphology at x < 1.5. The photoluminescence (PL) revealed intense and distinct emissions attributed to both the host and Tb3+ transitions. The emission intensity highly depends on the Alx moles. The International Commission on Illumination (CIE) colour chromaticity showed that the emission colour could be tuned by varying the Alx moles.

Synthesis of ZnO Polycrystalline Flakes Using Sol-Gel Method

2011 ◽  
Vol 320 ◽  
pp. 135-139
Author(s):  
Yung Kuan Tseng ◽  
Ming Hung Chuang ◽  
Yen Cheng Chen
Keyword(s):  
Crystal Structure ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Two Dimensional ◽  
Zno Nanostructures ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Polycrystalline Zinc ◽  
Scanning Electron

This study proposes a novel sol-gel method of fabricating the two-dimensional flakes polycrystalline zinc oxide (ZnO). Apply zinc acetate dehydrate in glycerol and hydrolyzed to get the precursor zinc alkoxide particles at 160°C, and self-assemble into flakes ZnO nanostructures, and then got higer crystallinity polycrystalline ZnO after calcination for one hour at 500°C. Field-emission scanning electron microscopy (FE-SEM) was used to observe the morphology of the flakes. Its size got to a few μm2. Analyze the crystal structure and crystallinity by X-ray powder diffraction (XRD). After calcination for one hour at 500°C, we can determine it is the hexagonal wurtzite structure of ZnO. And TGA/DSC to observe the loss and phase change of the solution. The Study has successfully synthesized ZnO polycrystalline flakes by sol-gel method.

FABRICATION AND CHARACTERISTICS OF ALN NANOWIRES

2001 ◽  
Vol 15 (30) ◽  
pp. 1455-1458 ◽  
Author(s):  
H. CHEN ◽  
X. K. LU ◽  
S. Q. ZHOU ◽  
X. H. HAO ◽  
Z. X. WANG
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sublimation Method ◽  
Scanning Electron

Single phase AlN nanowires are fabricated by a sublimation method. They were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), typical selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). The SEM and TEM images show that most of the nanowires have diameters of about 10–60 nm. The crystal structure of AlN nanowires revealed by XRD, SAED and HRTEM shows the AlN nanowires have a wurtzite structure.

Effects of La0.5Sr0.5CoO3 sol concentration on the microstructure and dielectric properties of Ba0.6Sr0.4TiO3 films prepared by sol-gel method on Ti substrate

2012 ◽  
Vol 1494 ◽  
pp. 253-258
Author(s):  
Dan Jiang ◽  
Songwei Han ◽  
Xuelian Zhao ◽  
Jinrong Cheng
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Sol Gel ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Bst Films ◽  
Scanning Electron

ABSTRACTBa0.6Sr0.4TiO3 (BST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO) buffered Ti substrates. Both BST and LSCO were prepared by sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of LSCO sol concentration on the crystallinity and surface morphology of the films. The results show that with the increase of LSCO sol concentration, BST films show variation of the structure and dielectric properties. BST films for LSCO of 0.2 mol/L exhibit a better crystallinity and improved dielectric properties, with the tunability, dielectric constant and tanδ of 30%, 420 and 0.028 respectively.

scholarly journals Nanocomposites Produced by Growth of Hydroxyapatite onto Silica Particles Prepared by the Sol-Gel Method

1996 ◽  
Vol 5 (1) ◽  
pp. 096369359600500 ◽  
Author(s):  
R. Rodríguez ◽  
J. Coreño ◽  
J.A. Arenas ◽  
V.M. Castaño
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Silica Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Silica Sols ◽  
Scanning Electron

The growth of hydroxyapatite, a calcium phosphate, on silica particles prepared by the sol-gel method is reported. The size of the silica sols was controlled by changing the pH of water before the mixing with the alcoxide. Particle size profiles of sols were obtained by using dynamical light scattering. The characterisation of the composites, of nanometer sizes, was performed by employing X-ray diffraction, scanning electron microscopy and Raman spectroscopy.

Synthesis of SnO2 by Sol-Gel Method

2016 ◽  
Vol 254 ◽  
pp. 200-206 ◽  
Author(s):  
Catalina Nuțescu Duduman ◽  
María Isabel Barrena Pérez ◽  
José Maria Gómez de Salazar ◽  
Ioan Carcea ◽  
Daniela Lucia Chicet ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Diffraction Pattern ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Sol Gel Process

Nanostructured SnO2 was prepared based on the sol-gel method used in the preparation of crystalline metal oxides. Sol-gel process can be described as a forming network of oxide polycondensation reaction of a molecular precursor in a liquid. Six experiments were carried out. Morphological structures and chemical composition were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) after calcination. It is noted that TEM images show that the spheres consist from nanocrystals, quantitative EDS analysis of the chemical composition shows an absence of the chlorine, which is a desired fact. For structural characterization of the material we used X-Ray Diffraction (XRD). The X-ray diffraction pattern for all samples indicates peaks which are agreeable with standard diffraction pattern of SnO2. The particle size of all samples was in the range of 28-92 nm calculated according to Scherrer equation.

scholarly journals The effects of varying the Eu3+ concentration on the structural and optical properties of Mg1.5Al2O4.5:x% Eu3+ (0 ≤ x ≤ 2) nanophosphors prepared by sol–gel method

2018 ◽  
Vol 8 ◽  
pp. 184798041880064 ◽  
Author(s):  
VM Maphiri ◽  
BF Dejene ◽  
TE Motaung ◽  
TT Hlatshwayo ◽  
OM Ndwandwe ◽  
...  
Keyword(s):  
Single Phase ◽  
Crystal Size ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
The Eu

Mg1.5Al2O4.5: x% Eu3+ (0 ≤ x ≤ 2) nanopowders were successfully synthesized via sol–gel method. The X-ray diffraction (XRD) spectrum revealed that the Mg1.5Al2O4.5: x% Eu3+ matches the single phase of face-centred cubic MgAl2O4. The estimated average crystallite sizes calculated using the XRD spectra were found to be in the order of 4 nm. The estimated crystal size was confirmed by the high-resolution transmission electron microscopy. The energy dispersive X-ray spectroscopy confirmed the presence of all expected elementary composition (Mg, Al, O and Eu). The field emission gun scanning electron microscope showed that varying the Eu3+ concentration influence the morphology of the prepared nanophosphor. The photoluminescence results showed that the host emits the violet colour at around 382 nm, which was attributed to the defects within the band gap ( Eg) of host material. The Eu3+-doped samples showed the emission at around 560, 580, 593, 618, 655 and 704 nm which are, respectively, attributed to the 5D1 → 7F3, 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 characteristic transitions in Eu3+. The International Commission on Illumination colour chromaticity showed that the Eu3+ doping influences the emission colour.

Using a Sol-Gel Method to Prepare the TiO2/CNTs Nanocomposite

2014 ◽  
Vol 529 ◽  
pp. 108-111 ◽  
Author(s):  
Sheng Hao Meng ◽  
Yan Jun ◽  
Hong Guang Li ◽  
Shi Guo Du
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Uniform Coating ◽  
Hydrolysis Of ◽  
Scanning Electron

Summarizd the methods of oxide coated on the surface of carbon nanotubes. Using carbon nanotubes (CNTs) as template, TiO2/CNTs nanocomposite was prepared by a sol-gel method. Urea as a promoter, obtained by the slow hydrolysis of tetrabutyl titanate Ti (OH)4 precursor is deposited on the carbon nanotubes, is further dehydrated to form TiO2. Its structure was characterized by X-ray energy spectroscopy (EDS) and scanning electron microscopy (SEM), and obtain uniform coating of TiO2/CNTs composites

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

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