Dielectric relaxation in Bi2O3–ZnO–Nb2O5 cubic pyrochlore

Frequency dispersion associated with dielectric relaxation phenomena in polycrystalline cubic pyrochlore with normal composition (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 is analyzed. Measurements at cryogenic temperatures and high frequencies reveal a broad distribution of relaxation times. The associated dielectric loss data can be modeled with a function convoluting the Vogel–Fulcher law and a Gaussian distribution. This function, dependent only on measuring frequency and temperature, describes exceptionally well the phenomena observed over a frequency range covering seven decades and over 300 K.

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