Low-temperature dielectric relaxation in the pyrochlore „Bi3Õ4Zn1Õ4...2„Zn1Õ4Ta3Õ4...2O7 compound

The dielectric behavior of the pyrochlore (Bi3/4Zn1/4)2(Zn1/4Ta3/4)2O7 compound has been studied. A low-temperature dielectric relaxation was observed in a low-permittivity matrix with «5;60. The dielectric relaxation process follows a modified Debye model in the vicinity of the relaxation peak, and the relaxation rate follows the Arrhenius law in the wide frequency range 10 to ;10 Hz. The temperature intensity of dielectric peaks are independent of dc bias ~<60 kV/cm!. The dielectric relaxation is tentatively attributed to the hopping of Zn/Bi ions at A sites with more than one equivalent potential minima, and the reorientation of the dipoles probably formed through interactions with the ‘‘seventh oxygen’’ and the Bi/Zn A-site ions in the pyrochlore (Bi3/4Zn1/4)2(Zn1/4Ta3/4)2O7 compound. © 2002 American Institute of Physics. @DOI: 10.1063/1.1486045#