Phases investigation in the antimony doped Bi2O3 system

The present study investigates the influence of Sb ions, introduced as dopants in α-Bi2O3, on the structure of the oxide polymorph forms obtained at high temperature. The structural changes of α-Bi2O3 for compositions in the system Bi2-xSbxO3 (x=0, 0.05, 0.1, 0.15, 0.2), at different thermal treatment temperatures were analyzed by thermal analysis, powder X-ray diffraction and infrared transmission spectroscopy. A tendency of the structure to change to a higher symmetry (monoclinic → tetragonal → cubic) was observed, as the content in antimony increased and the temperature reached 850 °C. The presence of Sb2O3 in the Bi2O3 oxide system promotes an oxygen release from the oxide and enlarges the stabilization domain of the δ-phase.