相对介电常数测试与模拟计算结合研究

摘要

采用频率谐振实验和第一性原理计算方法分别测试和计算了钛酸钡相对介电常数随频率的变化关系.谐振法测试结果表明,在100Hz～10kHz频率范围内,钛酸钡相对介电常数随频率从1250下降到150.第一性原理计算结果显示,光频下该材料相对介电常数数值较小且存在色散现象.两种方式对比研究有助于学生深入理解电介质相关极化理论.%By using the frequency resonance experiment and first-principle calculation method, the changeable relation of the relative dielectric constant frequency of barium titanate is tested and calculated.The resonance test results show that within the frequency range of 100 Hz-10 kHz, the relative dielectric constant of barium titanate decreases from 1,250 to 150.The first-principle calculation results show that the relative dielectric constant of the material is very small in optical frequency, and there is a dispersion phenomenon.Through the comparative research on the two different experimental methods, it is helpful for the students to obtain the deep understanding of the theory about dielectric polarization.