2012 Volume 61 Issue 2 Pages 57-63
To examine the effect of the valence of iron in starting material, the composites were manufactured from iron (II) and (III) sulfates by sol-gel method. The obtained gel were calcinated from 700 to 1000°C, and Mössbauer spectra of composites were obtained.
Mössbauer spectra showed that ε-Fe2O3 phase appeared in both composites. Iron (II) sulfate in the composites transformed to ε-Fe2O3 at lower calcination temperature than those of iron (III) sulfate, and that the content of ε-Fe2O3 phase appeared at higher temperature in composites prepared from iron (II) sulfate.
Magnetization measurement supported the results derived by Möossbauer effect measurement.