Combustion process in the synthesis of ZnO–Bi2O3

Combustion synthesis of homogeneous ZnO–Bi2O3 powder mixtures has been investigated, with emphasis on the reaction mechanism. The reaction uses salts containing the zinc and bismuth ion (oxidizer) and a fuel. The self-sustaining reaction leads to high temperatures that promote oxide formation and crystallization in a short period of time. The resulting ZnO–Bi2O3 powders show characteristics that favor applications in the field of electronic ceramics, such as varistors. Such characteristics, namely particle morphology and crystallinity degree, were accessed by X-ray diffraction and scanning electron microscopy, showing that combustion synthesis is a promising alternative method to produce adequate powders for the manufacture of varistors.