|
|
【答案】应助回帖
jxlcwy(金币+30, 翻译EPI+1): ★★★★★最佳答案 十分感谢 2012-02-21 19:16:39
|
Figure 4a and b respectively represent for the change curves of the dielectric constant of SiO2-CCTO ceramic along with frequency and the dielectric loss along with SiO2 content (1 MHz). According to the Figure 4a, the dielectric constant of each sample is relatively high at low frequencies, except for the sample with SiO2 content of 10wt%, the dielectric constants of all samples are above 10, but the high dielectric constant decreases rapidly along with the frequency increase; and when the frequency is greater than 3 kHz, the dielectric constant tends to be stable. Therefore, the high dielectric constant of the CCTO ceramic has great dependence on frequency. Research finds that CCTO is composed of semiconductor grains with insulating grain boundaries, a big difference in conductivity exists between the grain boundary and grain, so that a large number of charges accumulate at the grain boundaries, thus a large number of barrier layer capacitors are formed inside the ceramic, which is represented by high dielectric constant, especially more obvious at low frequency. |
|
回复此楼