## 3 Results and Discussion
### Surface Morphology Analysis of [Ni\({}_{x}Zn_{1-x}\)]Fe\({}_{2}\)O\({}_{4}\)  
Figure 7 shows the surface morphology of Ni\({}_{0.5}\)Zn\({}_{0.5}\)Fe\({}_{2}\)O\({}_{4}\) ferrite at different sintering temperatures, under an air atmosphere at 5 \({}^{\circ}\)C/min, held at a constant temperature for 2 h, and then furnace-cooled. From the figure, it can be seen that the non-sintered powder had a very small particulate diameter; the average diameter was about 10 nm. When the sintering temperature increased to 500 \({}^{\circ}\)C, the SEM image showed that there was no significant difference, as the average particulate diameter was still about 10 nm. When the sintering temperature increased to 600 \({}^{\circ}\)C, the average particulate diameter increased a little, and was about 20 nm. When the sintering temperature increased to 700 \({}^{\circ}\)C, there was not much difference from the product sintered 600 \({}^{\circ}\)C, as the average particulate diameter was still about 20 nm. When the sintering temperature increased to 800 \({}^{\circ}\)C, the average particulate diameter became significantly larger than that sintered at 700 \({}^{\circ}\)C, being about 30 nm. When the sintering temperature was 900 \({}^{\circ}\)C, the primary particles started to cluster, and some had already associated into secondary particles, with an average particulate diameter of about 50 nm. When temperature increased to 1000 \({}^{\circ}\)C, the primary particles started to cluster, and a massive amount of primary particles had already associated into secondary particles, the average diameter being 60 nm. At 1100 \({}^{\circ}\)C, it could be seen that secondary particles crystallized in massive amounts. At 1200 \({}^{\circ}\)C, secondary particles started to crystallize massively, and the crystallized particles were already larger than those crystallized at 1100 \({}^{\circ}\)C; the crystalline surface was filled with many particles with a size of about 200 nm. Ni\({}_{0.5}\)Zn\({}_{0.5}\)Fe\({}_{2}\)O\({}_{4}\) is shown in the figure with 100,000\(\times\) amplification on the field emission scanning electron microscope (FESEM). After comparison of the non-sintered product (a) andthat sintered at 500 \({}^{\circ}\)C (b), it can be seen that the nanoparticles sintered at 500 \({}^{\circ}\)C were larger than the non-sintered ones by 2-3 nm. Table 3 shows the mean diameter of the Cu\({}_{0.7}\)Zn\({}_{0.3}\)Fe\({}_{2}\)O\({}_{4}\) and Ni\({}_{0.5}\)Zn\({}_{0.5}\) Fe\({}_{2}\)O\({}_{4}\) are correlated with the SEM and XRD size estimations according to the thermal treatments. The mean diameter of the two compositions with the same sintering temperature trend is the same. The EDS composition analysis of Ni\({}_{0.5}\)Zn\({}_{0.5}\)Fe\({}_{2}\)O\({}_{4}\) showed that ferrite power was an alloy of Ni, Zn, Fe, and O. There were no other metallic ions present, and the proportion was correct, which proves that in the neutralization reaction process the metallic ions were completely precipitated. The Influence on the Magnetic Properties of [Ni\({}_{x}\)Zn\({}_{1-x}\)]Fe\({}_{2}\)O\({}_{4}\) When Cladded with TiO\({}_{2}\)  
Figure 8 shows the hysteresis curve for [Ni\({}_{x}\)Zn\({}_{1-x}\)]Fe\({}_{2}\)O\({}_{4}\) with different proportions, cladded with TiO\({}_{2}\). Here, [Ni\({}_{x}\)Zn\({}_{1-x}\)]Fe\({}_{2}\)O\({}_{4}\) can be used as the carrier of the optical catalyst TiO\({}_{2}\), to compare its effect on the magnetic properties. From the figure, it can be seen that the material with minimal saturated magnetization was (TiO\({}_{2}\))\({}_{07}\)/Ni\({}_{0.2}\)Zn\({}_{0.8}\)Fe\({}_{2}\)O\({}_{4}\), which had a saturated magnetization of only 1.603 M(emu/g). As the Ni content increased, the saturated magnetization also increased, and it reached a peak for (TiO\({}_{2}\))\({}_{07}\)/Ni\({}_{0.5}\)Zn\({}_{0.5}\)Fe\({}_{2}\)O\({}_{4}\), which had a saturated magnetization of about 10.364 M(emu/g). This trend was the same as that for [Ni\({}_{x}\)Zn\({}_{1-x}\)]Fe\({}_{2}\)O\({}_{4}\) not cladded with TiO\({}_{2}\).