Frequency and temperature dependence of the dielectric properties of ferroelectric materials

A review is given of the dielectric properties of some ferroelectric single crystal and polycrystalline bulk ceramics (LiTaO/sub 3/ single crystal, sol-gel derived PbZr/sub 0.53/Ti/sub 0.47/O/sub 3/ polycrystalline ceramic, SrBi/sub 2/Nb/sub 2/O/sub 9/ polycrystalline ceramics) over a wide frequency and temperature range. The properties were investigated by ac impedance spectroscopy. The measured data have been presented with different formalisms for better understanding the dielectric properties. 3D-graphs were used to present simultaneously both the frequency and temperature dependency of the dielectric properties. The great strength of this kind of analysis technique is that it is possible to characterize the different electrically-active regions in a ferroelectric material.