Influence of the Metal Nitrates to Citric Acid Molar Ratio on the Processing of Nickel Zinc Ferrite Nanocrystalline Powders Synthesized by a Sol-Gel Auto Combustion Method

2009 ◽  
Author(s):  
M. R. Barati ◽  
S. A. Seyyed Ebrahimi ◽  
A. Badiei ◽  
Mohamad Rusop ◽  
Tetsuo Soga
2008 ◽  
Vol 368-372 ◽  
pp. 598-600 ◽  
Author(s):  
M.R. Barati ◽  
S.A. Seyyed Ebrahimi ◽  
A. Badiei

In this work, nickel-zinc ferrite nanocrystalline powder has been prepared by a sol-gel autocombustion technique using nitrate-citrate gel obtained from metal nitrates and citric acid solution. Characterization of the nitrate-citrate gel, as-burnt powder and calcined powder at different calcination conditions were investigated by using XRD, FTIR and SEM techniques. The results revealed that the nitrate-citrate gel exhibits a self-propagating behavior after ignition and showed that the different calcination conditions affect the crystallite size of the synthesized powder as well as its phase constitution.


2008 ◽  
Vol 22 (18n19) ◽  
pp. 3153-3158 ◽  
Author(s):  
M. R. BARATI ◽  
S. A. SEYYED EBRAHIMI ◽  
A. BADIEI

In this research a sol-gel auto-combustion route has been proposed to synthesize nickel-zinc ferrite nanocrystalline powder, using metal nitrates, citric acid as fuel and ammonia as pH adjusting agent. The influence of pH value of the solution on phase evolution, crystallite size and morphology of as-burnt powders were investigated by XRD, SEM and TEM techniques. The results revealed that with pH=7 the single phase nickel-zinc ferrite nanocrystalline powders with crystallite size of about 27nm were formed directly after auto combustion process.


2012 ◽  
Vol 463-464 ◽  
pp. 1052-1056
Author(s):  
Ai Xiang Zeng ◽  
Jun Yuan

Ni0.6-xZn0.4MgxFe2O4were synthesized by sol-gel auto-combustion method with Zn(NO3.) 2 •6H2O. , Ni(NO3.) )2•6H2O. , Mg(NO3.) )2•6H2O. , Fe(NO3.) )3•9H2O. , COOO2. and NH3•H2O. X-ray diffraction (XRD) analysises show that the sample is single phase and the doping of magnesium makes no difference to nickel-zinc ferrite’s crystal structure; nickel-zinc ferrite has formed after auto-combustion. Scanning electron microscope analysises show that after sintered the sample’s size is more even and the doping of magnesium makes the size smaller and more even too.


2011 ◽  
Vol 25 (11) ◽  
pp. 855-861 ◽  
Author(s):  
M. SHAHMIRZAEI ◽  
S. A. SEYYED EBRAHIMI ◽  
R. DEHGHAN

In this work, a novel method of mechano sol–gel auto-combustion has been developed for production of single phase nickel ferrite nanocrystalline powder, consisting of a sol–gel auto-combustion synthesis followed by a high energy milling process before calcination. Sol–gel auto-combustion was carried out using a gel including citric acid as a reductant and metal nitrates as oxidants. This gel exhibited a self-propagating behavior after ignition in air. The effects of the intermediate high energy milling on the physical properties of the final product after calcination were investigated. The results showed that with a high energy milling of the sol–gel auto-combusted powders with a ball-to-powder mass ratio of 20 for 20 h, the temperature of calcination for synthesis of the single phase ferrite reduced from 1000°C to 700°C and the size of the ferrite crystallites decreased from 72 nm to 15 nm.


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