Synthesis of the β and δ phases of Bi2O3 stabilized by Gd2O3

We report here the synthesis of bismuth trioxide polymorphs in the binary system (BiO3)(1 - x)(Gd2O3)(x) (0.01 less than or equal to x less than or equal to 0.1) by adding small amounts of Gd2O3 into pure monoclinic alpha-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 O-Bi2O3 are 2 and 7 mole % respectively depending on heat treatment procedure. The delta-Bi2O3 phase could only be obtained with 9-10 mole % Gd2O3 addition.