TI-INDUCED AND MODIFIED DIELECTRIC RELAXATIONS IN PBZR1-XTIXO3 SINGLE-CRYSTALS (X-LESS-THAN-OR-EQUAL-TO-0.03) IN THE FREQUENCY-RANGE 10HZ-10MHZ

Three relaxation processes for frequencies from 10 Hz to 10 MHz and fo r various Ti concentrations in PbZr1-xTixO3 (x less than or equal to 0 .03) are presented. The lowest relaxation process (below 100 Hz in the paraelectric phase) is attributed to electrochemical processes contri buting to the dielectric polarization. The second is strong low-freque ncy dipolar relaxation (up to 1 kHz in the paraelectric phase) which h as a nearly monodispersive character and is related to the disorder in the oxygen sublattice. While for pure PbZrO3 the contribution of the dielectric step Delta epsilon, coming from this relaxation, to epsilon '(T) was temperature independent, for PbZr1-xTixO3 it becomes a functi on of temperature. The third relaxation in the range of a few kilohert z visible in the transient phase and above T-c appears because of Ti i ntroduction and comes from the interface dynamics of the polar regions in the paraelectric phase and motion of the domain walls in the inter mediate phase of ferroelectric properties.