Dielectric properties of cubic bismuth based pyrochlores containing lithium and fluorine

摘要

In this work dielectric properties of Bi_(1.5)Zn_(1-x)Li_xNb_(1.5)O_(7-x)F_x with x=0.25 were investigated in a 20 Hz-12 GHz frequency and 120-500 K temperature range and compared to that of regular cubic BZN (when x=0). Measurements showed that both ceramics have dipolar glass type dielectric dispersion with wide relaxation time distributions. Mean relaxation time follows Arrhenius law in the investigated frequency range, although Vogel-Fulcher law was anticipated.