ZnCo2O4 spinel was successfully prepared via co-precipitation
process starting from corresponding metal chlorides in aqueous
solutions at pH=13. Different calcination temperatures (400-500-
600-700-800-1000oC) and different Zn:Co molar ratios (1:2
- 1:2.5) were applied in an effort to prepare this important spinel with perfect specifications starting from cheap, easy to handle inorganic precursors and using a simple process. This process was chosen for its simple requirements and the ability to modify the resulting spinel characteristics by adjusting different parameters easily like mixing temperature, time and speed and the drying conditions. The resulting samples were characterized using x-ray powder diffraction (XRPD), Fourier transform Infra-Red spectroscopy (FT-IR), Differential thermal analysis (DTA). The coloration, crystallinity size, formation and decomposition of the resulting ZnCo2O4 were found to depend on the calcination temperatures, Zn:Co molar ratio and stirring time. Results showed that ZnCo2O4 spinel was formed at relatively low temperatures. All the samples shared a cubic structure with Fd3m space group.
Zinc Chromate was synthesised by Co-precipitation
method, The synthesised samples were characterized using
X-ray powder diffraction technology (XRD).
Set temperature synthesis at 250 ℃ .
Our research aims to prepare ZnFe2O4 system by
CO-precipitation method in aqueous solution,starting from the
raw materials, and then studying its structure and properties .After
finishing the preparation period, we divided the precipitate in two
parts , and then we added to one of them the hydrogen peroxide and
then we dried every part alone, grind it and then we heated it at
various temperatures for two hours .
This paper presents the results of analyzing 17 models with
nonlinear static analysis. The models are 5, 10 and 15-story framewall
structures with Re-entrant corners. The participations of frames
to resist the shear force range between 25% and 60%
.