Dielectric properties of bismuth-containing pyrochlores: A comparative analysis

Abstract

The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out. We examined the dielectric properties (including behavior in electric fields) of two pyrochlore compounds: BZN (presumably a composition close to Bi[Formula: see text]Zn[Formula: see text]Nb[Formula: see text]O[Formula: see text] ceramics with chemical disorder in both A and B cation sublattices and Bi2Ti2O7 single crystal with fully chemical ordered structure. The fundamental differences between the dielectric properties of the BZN ceramics and Bi2Ti2O7 single crystal were shown. In particular, in the dielectric relaxation behavior (which cannot be described via Arrhenius law in the Bi2Ti2O[Formula: see text] or in the influence of the electric fields on the dielectric permittivity (splitting of the field-cooled and zero-field-cooled behaviors was observed for Bi2Ti2O7 below estimated freezing temperature). The results of this study highlights the special role of Bi2Ti2O7 as a candidate material for studying aspects of geometric frustration related with pyrochlore structure in non-magnetic medium and specifies the future directions of research.