## 3 Results and Discussion
### Magnetization Analysis  
Magnetic field (H)-dependent magnetization (M) has been investigated via M-H hysteresis curves, measured at 50 K and 300 K, and are displayed in Figure 4. All samples showed soft ferromagnetic behavior with small coercivity, as shown in the inset of Figure 4. The values of saturation magnetization (Ms) for all samples have been displayed in Table 1. The saturation magnetization, measured at 300 K and 50 K, were found to be in the range 39-53 emu/g, as displayed in Table 1. These values agree with previously reported value for pure Ni, 50.62 emu/g [12]. We observed that saturation magnetization was enhanced at a lower temperature (50 K) as compared with room temperature (300 K), which is obvious. Additionally, we observed that the greatest saturation was demonstrated by Ni-Non-Magnetic wires, while it was reduced in the samples prepared with magnetic fields. [PERSON] et al. have also reported similar results, where Ni nanowires, assembled using external magnetic fields, exhibited lesser saturation compared with powder counterparts [2]. The reduction in the saturation magnetization of the samples prepared with magnetic fields may possibly be attributed to the shape of the magnetic field. The shape of the magnetic field mainly affects the strength of the magnetic field and the magnetic field gradient, inside the sample, and in a particular direction. It can be understood as follows: during the experiment, the sample solution was maintained between the magnets; the shapes of the magnetic fields used are been shown in Figure 1. In all the cases, the greatest magnetic field strengths were found for single magnets, and the smallest between fields generated due to two vertical magnets. Figure 3: (a–d) SEM images (**a**) Ni-Non-Magnetic; (**b**) Ni-Single; (**c**) Ni-Double; (**d**) Ni-Ring at 5 K\(\times\) magnification. In the case of Ni-Ring wires, the magnetic field strength was greatest at the center of the beaker, along the vertical axis of the ring passing through its center, and reduced towards the wall of the beaker. Therefore, the saturation magnetization observed in the Ni-Ring sample was the least. This observation indicates that the selection of the shape of the Ni-Ring wires is not a good indicator of the magnetic field strength. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Ms**} & \multicolumn{2}{c}{**K (\(\times\)10\({}^{4}\))**} \\  & \multicolumn{2}{c}{**(emu/g)**} & \multicolumn{2}{c}{**(erg/cm\({}^{3}\))**} \\ \cline{2-5}  & **300 K** & **50 K** & **300 K** & **50 K** \\ \hline
**Ni-Non-Magnetic** & 49.1 & 52.8 & 2.78 & 2.81 \\
**Ni-Double** & 49.0 & 52.6 & 2.33 & 2.75 \\
**Ni-Single** & 39.8 & 51.9 & 2.15 & 3.23 \\
**Ni-Ring** & 43.7 & 50.0 & 2.06 & 3.84 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Saturation magnetization (Ms), magnetocrystalline anisotropy (K) at 300 K and 50 K temperature. Figure 4: Room temperature magnetic hysteresis loop of Ni-Non-Magnetic, Ni-Double, Ni-Single and Ni-Ring; the inset shows hysteresis in the near H = 0 region. of the magnetic field during synthesis influences the saturation magnetization of the final product. Additionally, the possibility of rotation of the direction of magnetization of individual domains in different directions cannot be declined. Due to the rotation in the direction of magnetization of individual domains, the direction of net magnetic moment directs away from the direction of easy magnetization of the metal which is <111> for Ni [11]. On applying the external magnetic field during growth, the magnetic domains align in random orientations relative to the easy axis of the fcc-Ni. Similar behaviour has also been observed in earlier work [13]. Thus, during measurement, all magnetic domains are not completely aligned along the direction of easy magnetization, which thereby reduces the saturation magnetization of the samples. The lowest saturation magnetization observed in the Ni-Ring sample may be attributable to its surface roughness, which was the highest among the samples.