## 3 Results
### Magnetic Properties  
In order to study the magnetic behavior of the supported Co-Fe LDH and the cobalt ferrite nano-nets, the magnetization parameters were determined through the curves of magnetization against the magnetic field. The magnetization (M) was measured with the applied magnetic field (H) between \(-\)20 kOe and +20 kOe at 300 K by VSM to build M-H curves. The saturation magnetization (M\({}_{\mathrm{s}}\)), the remnant magnetization (M\({}_{\mathrm{r}}\)) and the coercivity (H\({}_{\mathrm{c}}\)) were summarized in Table 1 for the supported LDH, the nano-nets and the prepared nanoparticles of cobalt ferrite. By increasing the external magnetic field of strength (H), the M-H curve of the supported Co-Fe LDH indicated that the magnetization (M) increased reaching to saturation value at 10.69 emu g\({}^{-1}\) as shown in Figure 10a. Also, Figure 10a exhibited a hysteresis loop including two branches for the magnetization and demagnetization processes. This means that the supported Co-Fe LDH has ferromagnetic behavior. The amount of the reverse field for demagnetizing the ferromagnetic material to zero is coercivity (H\({}_{\mathrm{c}}\) = 2.6 Oe). The remnant magnetization (M\({}_{\mathrm{r}}\)) was 1.36 emu g\({}^{-1}\) when the external magnetic field returned to zero. This indicated that all domains of the supported Co-Fe LDH did not return to their original orientation when the external magnetic field decreased to zero. In the case of the cobalt ferrite nano-nets, it showed and S-type curve with a wide hysteresis loop, representing the behavior of ferromagnetism as shown in Figure 10b. The saturation magnetization (M\({}_{\mathrm{s}}\)) and remanant magnetization (M\({}_{\mathrm{r}}\)) of the nano-nets were 6.44 emu g\({}^{-1}\) and 2.3 emu g\({}^{-1}\); respectively. The coercitivity (H\({}_{\mathrm{c}}\)) of the nano-nets has been found at 1277 Oe. The prepared nanoparticles of cobalt ferrite revealed S-type curve with no hysteresis loop as shown in Figure 9. This is a typical behavior of superparamagnetism. By comparing with the prepared nanoparticles of cobalt ferrite, both the supported LDH and the nano-nets showed ferromagnetic behavior. However, the supported LDH and the nano-nets are composed of nanoparticles. It means that the morphology of the nanoparticles has an important role for controlling their magnetic properties. The low value of saturation magnetization of the nano-nets compared to the supported LDH and the nanoparticles could be explained in the light of morphology of the sample. Where, the nano-nets are composed of nanoparticles and nanowires \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Samples** & **M\({}_{\mathrm{s}}\) (emu g\({}^{-1}\))** & **M\({}_{\mathrm{r}}\) (emu g\({}^{-1}\))** & **H\({}_{\mathrm{c}}\) (Oe)** & **QS(M\({}_{\mathrm{r}}\)/M\({}_{\mathrm{s}}\))** \\ \hline CoFe\({}_{2}\)O\({}_{4}\)/Co-Fe LDH & 10.69 \(\pm\) 0.05 & 1.36 \(\pm\) 0.007 & 2.60 \(\pm\) 0.01 & 0.13 \\ CoFe\({}_{2}\)O\({}_{4}\) nano-nets & 6.44 \(\pm\) 0.03 & 2.30 \(\pm\) 0.01 & 1277 \(\pm\) 6 & 0.36 \\ CoFe\({}_{2}\)O\({}_{4}\) nanoparticles & 11 \(\pm\) 0.05 & 0.25 \(\pm\) 0.001 & 35 \(\pm\) 0.2 & 0.023 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Magnetic data for the cobalt ferrite-supported LDH, cobalt ferrite nano-nets, and cobalt ferrite nanoparticles. Figure 9: TEM images and magnetization M–H curves of the CoFe\({}_{2}\)O\({}_{4}\) nanoparticles. in addition to vacancies and holes. The presence of vacancies and interatomic spacing caused low magnetization in the nano-nets of the ferrite [33; 34]. On the other side, the nano-nets have a coercive field value (1277 Oe) that is higher than the prepared nanoparticles of cobalt ferrite (35 Oe) and the bulk ferrite (980 Oe) [35]. The previous work [36] concluded that the morphology of the crystals has effect on the coercivity in this order: octahedral > cubes > spheres in line with the rise in the number of magnetic axes along this arrangement of forms.