Low sintering temperature of MgTiO 3 for type I capacitors

Abstract

Magnesium titanate MgTiO 3 is a well-known compound for type I multilayer ceramic capacitors. Nevertheless, the sintering temperature of the pure ilmenite MgTiO 3 is around 1350 °C. Such a high sintering temperature together with the high sensitivity of the dielectric material to reduction when heated in a low-oxygen containing atmosphere implies that MgTiO 3-based MLCC include palladium-rich inner electrodes. The high level of variation of both the costs of Pd and Ag justifies research leading to the use of cheaper metals such as silver or base metals such as nickel or copper. When using low-melting temperature metals (silver melts at 960 °C and copper at 1085 °C), the sintering temperature of the dielectric material has to be lowered. We report here on our investigations into the use of fluorine containing additives for the reducing of the sintering temperature of magnesium titanate, showing the ability of this material to be sintered at temperatures much lower than 1000 °C. Both dielectric and electric properties of such ceramics are compatible with type I capacitors requirements.