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. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved.