A Non-Alkoxide Sol−Gel Method for the Preparation of Homogeneous Nanocrystalline Powders of La0.85Sr0.15MnO3

2006 ◽  
Vol 18 (7) ◽  
pp. 1928-1937 ◽  
Author(s):  
Christopher N. Chervin ◽  
Brady J. Clapsaddle ◽  
Hsiang Wei Chiu ◽  
Alexander E. Gash ◽  
Joe H. Satcher, ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Synthesis and Characterization of Nanocrystalline ZnO Doped with Al3+ and Ni2+ by a Sol–Gel Method Coupled with Ultrasound Irradiation

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 406 ◽  
Author(s):  
M. Robles-Águila ◽  
J. Luna-López ◽  
Álvaro Hernández de la Luz ◽  
J. Martínez-Juárez ◽  
M. Rabanal
Keyword(s):  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Ultrasound Irradiation ◽  
Morphological Properties ◽  
Nanocrystalline Powders ◽  
Metallic Ions ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Zinc oxide is one of the most important semiconducting metal oxides and one of the most promising n-type materials, but its practical use is limited because of both its high thermal conductivity and its low electrical conductivity. Numerous studies have shown that doping with metals in ZnO structures leads to the modification of the band gap energy. In this work, Al-doped ZnO, Ni-doped ZnO, and undoped ZnO nanocrystalline powders were prepared by a sol–gel method coupled with ultrasound irradiation, and the results show the influence of Al3+ and Ni2+ ions in the ZnO network. The doping concentrations in ZnO of 0.99 atom % for ZnO–Al and 0.80 atom % for ZnO–Ni were obtained by X-ray Fluorescence (XRF). X-ray Diffraction (XRD) and Raman Spectroscopy showed a decreased intensity and broadening of main peaks, indicating metallic ions. The crystallite size of the sample was decreased from 24.5 nm (ZnO) to 22.0 nm (ZnO–Al) and 21 nm (ZnO–Ni). The textural and morphological properties were analyzed via Nitrogen Adsorption (BET method) and Field Emission Scanning Electron Microscopy (FESEM).

CO Sensing Properties of La1-xCaxFeO3 Perovskite Nanocrystalline Materials

2011 ◽  
Vol 495 ◽  
pp. 323-326 ◽  
Author(s):  
Ming Zhao ◽  
Li Hui Sun ◽  
Ji Fan Hu ◽  
Hong Wei Qin
Keyword(s):  
Response Time ◽  
Nanocrystalline Materials ◽  
Recovery Time ◽  
Operating Temperature ◽  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Orthorhombic Structure ◽  
Gel Method ◽  
Sensing Properties ◽  
Sol Gel Method

The La1-xCaxFeO3 nanocrystalline powders were prepared by sol-gel method. These powders crystallized as perovskite orthorhombic structure. With an increase of Ca content, the resistance of La1-xCaxFeO3 sensors in air decreases at first, undergoes a minimum at x=0.3, and then increases again. La1-xCaxFeO3-based sensors show sensitive responses to CO. Among those La1-xCaxFeO3-based sensors, the sensor with x=0.2 shows the highest response to 200 ppm CO at operating temperatures below 325°C. The highest response S=(RCO-Rair)/RCO for the La0.8Ca0.2FeO3 based sensor to 200 ppm CO is 87% with response time 15 s and recovery time 60 s at an operating temperature of 100°C.

CONTROLLED SYNTHESIS AND CHARACTERIZATION OF TiO2 NANOPARTICLES VIA A SOL–GEL METHOD

2004 ◽  
Vol 03 (06) ◽  
pp. 749-755 ◽  
Author(s):  
YING LI ◽  
SUO HON LIM ◽  
TIM WHITE
Keyword(s):  
Sol Gel ◽  
Critical Role ◽  
Rietveld Analysis ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
Gelation Temperature ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron

The properties influencing the photocatalytic activity of TiO 2 particles have been suggested to include the surface area, crystallinity, crystallite size and crystal structure. Therefore, manipulation of the microstructure of titania, especially of nanocrystalline powders, is very important in the preparative process. In this study, nanocrystalline TiO 2 powders with controlled particle size and phase composition were synthesized at low temperature (<80°C) by a modified sol–gel method. The effects of gelation temperature were systematically investigated. It was found that this parameter played a critical role in determining the crystallinity of single phase anatase. With increasing gelation temperature, the crystallinity of anatase improved initially and then decreased if the temperature was raised to 80°C. These nanomaterials were characterized comprehensively by powder X-ray diffraction (including Rietveld analysis), high-resolution transmission electron microscopy, DSC/TGA thermal analysis and UV–Vis spectrometry.

scholarly journals A Non-Alkoxide Sol—Gel Method for the Preparation of Homogeneous Nanocrystalline Powders of La0.85Sr0.15MnO3.

ChemInform ◽  
2006 ◽  
Vol 37 (25) ◽  
Author(s):  
Christopher N. Chervin ◽  
Brady J. Clapsaddle ◽  
Hsiang Wei Chiu ◽  
Alexander E. Gash ◽  
Joe H. Jr. Satcher ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Gel Method ◽  
Sol Gel Method

Preparation of SnO2-CuO nanocrystalline powders in two different ways by the sol-gel method

1996 ◽  
Vol 156 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Guojia Fang ◽  
Zuli Liu ◽  
Zengchang Zhang ◽  
Yifan Hu ◽  
I. A. Ashur ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Gel Method ◽  
Sol Gel Method

Preparation of CuNb2O6 nanocrystalline powders by sol–gel method

2009 ◽  
Vol 477 (1-2) ◽  
pp. 716-719 ◽  
Author(s):  
Ying Chun Zhang ◽  
BaoJian Fu ◽  
Qiang Liu
Keyword(s):  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Synthesis of Nanocrystalline-Doped ZnO with Al3+ and Ni2+ by Sol-Gel Method Coupled by Ultrasound Irradiation

2018 ◽  
Author(s):  
M. J. Robles-Águila ◽  
J. A. Luna-López ◽  
Álvaro D. Hernández de la Luz ◽  
J. Martínez-Juárez ◽  
M. E. Rabanal
Keyword(s):  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Ultrasound Irradiation ◽  
Band Gap Energy ◽  
Nanocrystalline Powders ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Bet Method ◽  
Doped Zno

Zinc oxide is one of the most important semiconductor metal oxides and one of the most promising n-type materials, but its practical use is limited because of both its high thermal conductivity and its low electrical conductivity. Numerous studies have shown that doping with metals in ZnO structures leads to the modification of the band gap energy. In this work, Al-doped ZnO, Ni-doped ZnO, and undoped ZnO nanocrystalline powders were prepared by sol-gel method coupled with ultrasound irradiation. The doping concentration in ZnO was 1.0 at.% of Al and Ni. Influence of Al3+ and Ni2+ ions in the ZnO network are explored in this paper. X-ray Diffraction (XRD), Raman Spectroscopy, Nitrogen Adsorption (BET method), X-Ray Fluorescence (XRF) and Field Emission Scanning Electron Microscopy (FESEM) analyses demonstrated the incorporation of metal ions (aluminum and nickel) into the ZnO wurtzite structure. The crystallite size of the sample was decreased from 24.5 nm (ZnO) to 22.0 nm (ZnO-Al) and 21 nm (ZnO-Ni).

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