【摘要】 利用计算机自动控制的超低频介电谱测量装置和HP4192A阻抗分析仪,在10-4Hz-105Hz宽达九个数量级的范围内测量了钛酸锶陶瓷的频域介电谱.其频域复介电常数可很好地拟合为两项之和.其中超低频项来自于晶界间空间电荷运动的贡献,高频项来自于晶粒内部空间电荷运动的贡献.高频项复介电常数的实部在频率增大时变为负值,这说明介电谱用频域方法来描述是有缺陷的,其测量结果无法用传统的介电极化理论加以解释.更多还原

【Abstract】 By using computer controlled ultra-low frequency dielectric spectrometer and HP4124A impendence analyzer, we measured the frequency domain dielectric spectrum of SrTiO3 ceramics in the frequencies from 10-4Hz to 105Hz. The complex dielectric constants obtained can be well extracted into the summation of two components. The lower frequency one can probably attribute to the motion of space charges in grain boundaries, the higher frequency one can attribute to that within the grains. Further, real permittivity of the latter component changes to be below zero at high frequencies. It indicates that frequency domain method is not a proper method for describing dielectric spectroscopy, while the experimental results can not be explained by traditional dielectric polarization theory.更多还原