Synthesis of the β and δ Phases of Bi2O3 Stabilized by Gd2O3

Abstract

We report here the synthesis of bismuth trioxide polymorphs in the binary system (BiO₃)_1-x(Gd₂O₃)_x( 0.01 ≤ x ≤ 0.1) by adding small amounts of Gd₂O₃ into pure monoclinic α-Bi₂O₃. We also studied on the polymorphic changes, crystallographic properties and Gd₂O₃ content dependence of the lattice parameters of the phases investigated. We found that minumum and maximum solubility for Gd₂O₃ in β-Bi₂O₃ are 2 and 7 mole % respectively depending on heat treatment Procedure. The δ=Bi₂O₃ phase could only be obtained with 9–10 mole % Gd₂O₃ addition.