Fabrication of the SiOC/HfO2 Ceramic Composites by the Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 912-915
Author(s):  
Dai Shou ◽  
Ding Shan Ruan ◽  
Feng Hou

In this paper, Hf element was introduced into the Si-O-C network by the sol-gel method using the dimethyldiethoxysiloxane (DMDES, (CH3)2Si(OC2H5)2) and hafnium tetra(n-butoxide) (HfOR, Hf(OC4H9)4) as raw materials. The SiOC/HfO2 ceramic composite was obtained by pyrolyzing Si-Hf-O-C gel at 1000 °C in argon. FT-IR spectra revealed the presence of Si-O-Hf peaks at 932 cm-1. The weight loss of the as-prepared SiOC/HfO2 was about 0.2 wt.% under argon atmorsphere up to 1550 °C, which was much lower than the hafnia-free SiOC composites and exhibited a remarkable improved thermal stability.

2012 ◽  
Vol 557-559 ◽  
pp. 1457-1460 ◽  
Author(s):  
Chang Bin Xia ◽  
Chun Hua Liu ◽  
Dao Xin Wu

TiO2/bamboo charcoal complex photocatalysts has been prepared for tetra-n-butyltitanate as titanium source, bamboo carbon (BC) as the carrier with Sol-Gel method.it Characterizations were analyzed using TGA, DSC, SEM, XRD, DRS (diffuse reflective spectrum) and FT-IR spectra.


2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.


2021 ◽  
Vol 219 (1) ◽  
pp. 247-259
Author(s):  
Jing Yang ◽  
Yuzhi Ai ◽  
Wangqing Fan ◽  
Ruihua Mu ◽  
Xi Chen ◽  
...  

2013 ◽  
Vol 745-746 ◽  
pp. 673-678 ◽  
Author(s):  
Wei Hui Jiang ◽  
Zhi Fang Xu ◽  
Jian Min Liu ◽  
Qing Xia Zhu ◽  
Quan Zhang

Aluminum titanate (Al2TiO5) powder has been synthesized at low temperature via nonhydrolytic sol-gel method by using aluminum powder as aluminum source, titanium tetrachloride as titanium source, anhydrous ethanol as oxygen donor with different catalysts. The phase transformation of aluminum titanate xerogel powder during heat treatment and the influence of the mixing orders of raw materials, catalyst kinds on the synthesis of aluminum titanate were investigated by means of differential-thermal analysis (DTA-TG), X-ray diffraction (XRD), transmission electron microscope (TEM). The results indicated that aluminum titanate powder was easily synthesized at 750 °C by using AlCl3 as catalyst with a mixing order of adding TiCl4 before AlCl3 into aluminum alcohol mixture. The catalytic order of the different catalysts in the preparation process of aluminum titanate is: FeCl3> AlCl3> MgCl2. The catalyst promoted the activation of metal aluminum powder and played a major role in the synthesis of aluminum titanate powder at low temperature via nonhydrolytic sol-gel method.


2013 ◽  
Vol 712-715 ◽  
pp. 257-261
Author(s):  
Yin Lin Wu ◽  
Qing Hui Wang ◽  
Ling Wang ◽  
Hai Yan Zhao

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.


2020 ◽  
Vol 842 ◽  
pp. 121-126
Author(s):  
Ji Hui Luo ◽  
Qiu Yue Wen ◽  
Shu Liu ◽  
Ting Liu ◽  
Su Ting Wei ◽  
...  

TiO2 films were prepared by sol-gel method with butyl titanate, anhydrous ethanol, acetyl acetone and hydrochloric acid as raw materials, which were sintered at 380 °C and 530 °C respectively to obtain TiO2 films. XRD was used for analyzing the crystal structure of TiO2 film, and ImageJ software was used to detect the light transmittance of TiO2 film samples. The results show that the film sintered at 530 °C is brookite structure and the film sintered at 380 °C is anatase structure. The increase of sintering temperature is not conducive to the growth of TiO2 film grains. TiO2 films sintered at 380 °C have good light transmittance.


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