Electrical conductivity study of the solubility limits of tin–antimony mixed perovskites

Abstract

A series of tin–antimony mixed-oxide perovskites of the ABO₃ type with A = Ba and B = Sn_1–xSb_x was synthesized using increasing amounts of antimony. The electrical conductivity of these solids was studied to try to detect a possible solid solution phase and to determine the valence state of the cations.

Antimony dissolves in the stannic sites of the stannate perovskite structure up to a mole fraction of 0.17 in a pentavalent state (Sb⁵⁺). Above this limit, the variations in electrical conductivity have been ascribed to the formation of an insulating second solid phase whose existence was confirmed by X-ray analysis (formation of the antimonate pyrochlore structure, Ba₂Sb₂O₇).