## 3 Results and Discussion  
### Structure by XRD, Raman and FTIR  
XRD diffraction patterns in Figure 1a show the main diffraction crystallographic planes at 20 = 30.2\({}^{\circ}\), 35.4\({}^{\circ}\), 37.1\({}^{\circ}\), 43.4\({}^{\circ}\), 56.9\({}^{\circ}\) and 62.5\({}^{\circ}\), which are attributed to be from the (220), (311), (400), (422), (511) and (440) planes, respectively. These peaks were indexed to a standard pattern of the inverse cubic spinel Fe\({}_{3}\)O\({}_{4}\) phase, e.g., magnetite with file JCPDS 85-1436, in agreement with some reports [22]. Hence, co-precipitating aqueous solutions of iron sulphate precursors, e.g., Fe\({}^{2+}\)/Fe\({}^{3+}\) ions mixtures in a basic medium with sucrose promotes the formation of iron hydroxides (Fe(OH)\({}_{3}\)) and oxyhydroxides (\(\alpha\)-FeOOH). Subsequently, the former ferrous hydroxides nucleate and grow forming the oxyhydroxides in the presence of OH\({}^{-}\) ions from ammonia solution and sucrose. Finally, the oxyhydroxides can be converted into magnetite after hydrothermal treatment and drying at 80 \({}^{\circ}\)C overnight, as in the case of FeC and Fe/FeC composites. These observations are in accordance with the findings [23; 24]. The broad features of the Fe-based composites diffractograms suggest the crystalline nature of the magnetite particles. Additionally, it is found that the peaks at \(2\theta=35.4^{\circ}\) (311) and \(62.7^{\circ}\) (440) are ascribed to the cubic spinel \(\gamma\)-Fe\({}_{2}\)O\({}_{3}\) phase (maghemite, JCPDS 01-089-5892), which are indeed in similar positions as those of magnetite [25]. As the diffraction peaks are broad due to the quantum confinement effect of the iron particles, the lattice parameters of the magnetite and maghemite phases are closely related and difficult to resolve. Thus, it is not direct to achieve an accurate distinction between magnetite and maghemite phases by powder XRD and hence, a more profound study is beyond motivation and goals of this particular study. Thus, asterisks symbols were used on magnetite patterns to label maghemite as an impurity. Unlike the composites, which have broad peaks, the pattern of the Fe sample has narrow XRD peaks due to the particles growth and reduction of strain in the lattice originating from defects. Besides, the XRD pattern of Fe sample exhibits poorly crystalline peaks at \(2\theta\) values of \(21.5^{\circ}\), \(33.5^{\circ}\), \(36.9^{\circ}\), \(41.4^{\circ}\), \(53.5^{\circ}\) and \(59.3^{\circ}\) corresponding to the (110), (130), (111), (210), (131) and (211) planes of the hexagonal \(\alpha\)-FeO(OH) phase (goethite, JCPDS 03-0249), as found elsewhere [23; 26]. Furthermore, peaks at \(2\theta\) values of \(23.9^{\circ}\), \(30.3^{\circ}\), \(34.8^{\circ}\), \(38.7^{\circ}\), \(41.3^{\circ}\), \(47.5^{\circ}\), \(58.7^{\circ}\) and \(63.6^{\circ}\) unambiguously match well with the (012), (104), (110), (113), (024), (116), (214) and (300) planes of the rhombohedral \(\alpha\)-Fe\({}_{2}\)O\({}_{3}\) phase (hematite) file JCPDS 33-0664. Similar to other observations, the appearance of hematite in the final product is due to hydrolysis of the excessive Fe\({}^{3+}\) ions, when the Fe\({}^{2+}\)/Fe\({}^{3+}\) molar ratio present in the solution may be above 2 [24]. Obviously, the diffraction peaks of both magnetite and maghemite facets cannot be ruled out in Fe sample. This result indicates that the preparation method of Fe sample creates a  
Figure 1: Structural characterizations by (a) XRD, (b) Raman and (c) FTIR measurements. The asterisks mean the presence of the maghemite phase. mixture of the hematite, maghemite and magnetite oxides as well as goethite oxyhydroxide with the predominant phase being magnetite with more than 70% of the phase contributions. Raman spectra of all solids are shown in Figure 1b.