scholarly journals Preliminary study on the growth mechanism of zircon whiskers prepared via non-hydrolytic sol-gel method combined with carbon black as reducing agent

2018 ◽  
Vol 12 (2) ◽  
pp. 95-99
Author(s):  
Guo Feng ◽  
Feng Jiang ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Sanhai Wang ◽  
...  

Zircon whiskers were prepared at 700?C via non-hydrolytic sol-gel method combined with carbon black as reducing agent, Si(OC2H5)4 (TEOS) and ZrCl4 as precursors and LiF as mineralizer. The whiskers were characterized and their growth mechanism was discussed. The results show that the introduction of carbon black is beneficial for the preferential axial growth of zircon crystals into whiskers. The diameter and aspect ratio of zircon whiskers are 30-40 nm and 6-15, respectively. The zircon whiskers grow along the [001] direction, which is c-axis oriented. The growth mechanism is revealed to be the screw dislocation mechanism with the mass transport mainly from the zircon crystal particle matrix.

2011 ◽  
Vol 412 ◽  
pp. 223-226 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yan Hui Yang ◽  
Qing Xia Zhu ◽  
Jian Min Liu

ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.


2011 ◽  
Vol 8 (s1) ◽  
pp. S189-S194 ◽  
Author(s):  
Yong-Qing Zhai ◽  
Jing Qiao ◽  
Zhang Zhang

With activated carbon for reducing agent, the sol-gel method was used to prepare the giant magnetoresistance materials Sr2FeMoO6, which is the double Perovskite oxide. The structure, morphology, magnetic and electrical transport properties were investigated respectively by x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The as-synthesized sample is Sr2FeMoO6with tetragonal crystal structure and I4/mmm space group and unit cell parameter is a = 5.580Å, c = 7.882Å. The primary particles are spherical in shape and the grain size is below 100 nm. The curie temperature is above room temperature and the saturation magnetization is 13.321 A·m2/kg under 1.0 T at room temperature. The sample exhibit typical semiconductor behavior and the conductive mechanism can be described by small polaron variable range hopping model. The room temperature magnetoresistance of the sample under 1.0 T field is up to -10.02%. Moreover, it is found the dosage of citric acid and the amount of reducing agent has great effect on the phase structure and magnetic properties of the samples.


2014 ◽  
Vol 29 (8) ◽  
pp. 807
Author(s):  
WANG Min ◽  
NIU Chao ◽  
DONG Zhan-Jun ◽  
CHE Yin-Sheng ◽  
DONG Duo ◽  
...  

2011 ◽  
Vol 10 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Ramona-Crina Suciu ◽  
Marcela Corina Rosu ◽  
Teofil Danut Silipas ◽  
Emil Indrea ◽  
Violeta Popescu ◽  
...  

Author(s):  
Dong XU ◽  
Qi SONG ◽  
Ke ZHANG ◽  
Hong-Xing XU ◽  
Yong-Tao YANG ◽  
...  
Keyword(s):  
Sol Gel ◽  

2009 ◽  
Vol 24 (4) ◽  
pp. 848-852 ◽  
Author(s):  
Cheng-Shun LI ◽  
Yu-Jun ZHANG ◽  
Jing-De ZHANG

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