LOW-FREQUENCY DIELECTRIC-DISPERSION OF THE K3LI2NB5O15 FERROELECTRIC CERAMICS

The dielectric and impedance spectroscopy of potassium lithium niobate , K3Li2Nb5O15(KLN), ceramic has been investigated over the frequency r ange of 100 Bz to 1 MHz. Low-frequency dielectric dispersion was obser ved near the Curie temperature (T-c approximate to 500 degrees C). In the a.c. complex impedance spectra as a function of temperature and fr equency, impedance relaxation was found as two types of dispersions. O ne may be caused by intrinsic polarization, the other by mobile carrie r. In the vicinity of the transition temperature, the dielectric const ant was strongly influenced by the polarization due to the conduction of charge carriers. This implies regards that the conduction of charge carriers contributes a great deal to low-frequency dielectric dispers ion.