The pH of solutions prepared from FeCl middot H O
The strongest peak observed in Fig. 2 at 2θ of 38.3 and 44.5 corresponds to hematite, HP (2,1,1) and iron, syn (1,1,0) with a DB card number of 01-072-6233 and 01-089-71, respectively. Further, the result revealed that higher pH and heating resulted in strong and well resolved peaks than the one synthesised at lower and ambient temperature. When iron MNPs synthesised at pH 11.5 without heat (composed of 51% maghemite–Q syn (γ-Fe2O3), 26% magnetite (Fe3O4), 22% hematite (α-Fe2O3) with average particle size of 6.5, 6.5, and 6.8 nm respectively, and 1% other forms of iron oxide) was calcinated at 500 °C; all transformed to α-Fe2O3 (99%, with average particle size 31.3 nm) and with trace amount of magnetite and goethite (α-FeOOH).