Study about some two main dopants for a ZnO based varistor material with 5 additives, applied in overvoltage protection equipment

Metal Oxide Varistors are, as electrical materials, composite ceramics, behaving like n - semiconductors, based on a poly-crystalline and complex physical and chemical structure. The application domain of these state of the art power electronic devices is mostly the overvoltage protection equipment (designed for every voltage level), based on some major advantages such as: a very high level of non-linearity between the resulting crossing current and the applied voltage characteristic, a high energy adsorption capacity and an excellent rapid response time, which make them suitable for protecting any other sensible electronic devices and pieces of circuits. This paper describes a new electronic material and some manufacturing technology issues of a Metal Oxide Varistor, based on some new mixtures of oxides used to obtain a new ceramic material with higher non-linear electric properties. The two dopant oxides taken in consideration are Sb₂O₃ and Co₃O₄ as additives. All measurements of the electrical behavior were carried out in relation with a classic 5 dopants material (other three + these two ones).