The formation and stability of a body-centered-cubic γ-Bi2O3 solid solution in the Bi2O3-ZnO system

Minor additions of ZnO to Bi2O3 result in the transformation of the face-centered-cubic crystal structure of the high-temperature polymorph of Bi2O3 to a body-centered-cubic solid solution (gamma-Bi2O3). In the binary system Bi2O3-ZnO, the b.c.c.-solid solution exists in the Bi2O3-rich part of this system and extends to a composition of 1.5 mol% ZnO. Beyond the solid-solubility limit, the solid solution coexists with a binary compound Bi38ZnO58. On cooling below 700 degreesC, the gamma-Bi2O3 solid solution transforms to the low-temperature monoclinic polymorph alpha-Bi2O3 and Bi38ZnO58.