Effects of acceptor and donor additives on the properties of MgTiO3 ceramics sintered under reducing atmosphere

Sintered in reducing atmospheres, MgTiO3 ceramics are known to own ionised oxygen vacancies and conduction electrons which give rise to very poor insulation resistance. Prompted by the example of BaTiO3 ceramics where acceptor doping agents can trap the conduction electrons and donor doping agents compensate the acceptors in place of oxygen vacancies (Hagemann, H. and Hennings, D., Reversible weight change of acceptor-doped BaTiO3. J. Am. Ceram. Soc., 1981, 64, 590–594), we have investigated on the effects of Mn acceptor and W donor doping agents on the properties of MgTiO3 ceramics sintered under a reducing atmosphere of moist N2–1%H2. Resistivities higher than 105 MΩ.cm have effectively been obtained in these doped ceramics and dielectric constant of pure MgTiO3 was proved not to be modified by the presence of doping agents. In order to study the possibility of employing these materials in the production of type-I ceramic multilayer capacitors with base-metal electrodes, co-sintering tests with nickel were investigated.