## 3 Results and Discussion
This is manifested as higher temperature stability of the resistivity of \(\text{Si}_{3}\text{N}_{4}\) ceramics at the macro level. The migration process of carriers inside ceramics is shown in Figure 4.  
The relationship between the dielectric constant and frequency of Si\({}_{3}\)N\({}_{4}\) ceramic materials is shown in Figure 5. When the ratio of Y\({}_{2}\)O\({}_{3}\) to Al\({}_{2}\)O\({}_{3}\) in the sintering aid was 5:3, the dielectric constant of Si\({}_{3}\)N\({}_{4}\) ceramic materials gradually increased with the increase in sintering aid addition. At a frequency of 50 Hz, the dielectric constants of the 1825-5Y-92 SN, 1825-6.25Y-90 SN, and 1825-7.5Y-88 SN samples were 7.89, 8.35, and 8.50, respectively. The ratio of sintering aid had little effect on the dielectric constant of Si\({}_{3}\)N\({}_{4}\) ceramic materials. With the increase in frequency, the dielectric constant of the composite material slowly decreases, which is mainly related to interface polarization. The polarization of Si\({}_{3}\)N\({}_{4}\) ceramic composite materials under the action of an electric field is not instantaneous but has a certain polarization time. Therefore, interface polarization plays a dominant role at low frequencies. With the increase in frequency, interface polarization cannot follow the changes of high-frequency electric fields, and interface polarization gradually disappears, resulting in a gradual decrease in the dielectric constant of the composite material. The relationship between dielectric constant and temperature of Si\({}_{3}\)N\({}_{4}\) ceramics at 50 Hz is shown in Figure 6. It can be seen that the dielectric constant of Si\({}_{3}\)N\({}_{4}\) ceramics gradually increased with the addition of additives at 50 Hz, but the proportion of Y\({}_{2}\)O\({}_{3}\) to Al\({}_{2}\)O\({}_{3}\) had little effect on the dielectric constant at 50 Hz. In addition, the temperature range of 20-80 \({}^{\circ}\)C had little influence on the dielectric constant of Si\({}_{3}\)N\({}_{4}\) ceramics; for example, the dielectric constants of sample 1825-7.5-Y-88 Sn at 20-80 \({}^{\circ}\)C were 8.50, 8.53, 8.55, and 8.56, respectively. The dielectric constant increases slightly with the increase in temperature, which may be caused by ion migration at high temperature. [PERSON] et al. found that the dielectric constant of Si\({}_{3}\)N\({}_{4}\) ceramics was mainly affected by the content of additives and density rather than the crystallinity of the second phase. In the experiments, the density of all samples was higher than 99%, so the dielectric constant of the samples hardly changed [23]. Figure 2:0 Mechanism of carrier migration in Si\({}_{3}\)N\({}_{4}\) ceramics. Figure 2:1 Relationship between dielectric constant and frequency of Si\({}_{3}\)N\({}_{4}\) ceramic materials. The relationship between the dielectric loss and frequency of Si\({}_{3}\)N\({}_{4}\) ceramics is shown in Figure 2:2 It can be seen that when the frequency was greater than 100 Hz, the dielectric loss increased with the increase in sintering aid content. This is mainly due to the increase in sintering aid content, which increases the carrier concentration inside the ceramic material. At low frequencies (less than 50 Hz), the dielectric loss of the composite material is mainly affected by interface polarization and the distribution state of sintering aids. Similar to the dielectric constant, interface polarization plays a dominant role at low frequencies. From the previous microscopic morphology of Si\({}_{3}\)N\({}_{4}\) ceramic material surfaces, it can be seen that when the ratio of Y\({}_{2}\)O\({}_{3}\) to Al\({}_{2}\)O\({}_{3}\) was 5:5, due to the higher content of Al\({}_{2}\)O\({}_{3}\), abnormally large \(\beta\)-Si\({}_{3}\)N\({}_{4}\) grains were formed.