Relationship between wetting and electrical contact properties of pure metals and alloys on semiconducting barium titanate ceramics

In this work, the relationship between the thermodynamic properties of metal-ceramic interfaces and their electrical contact properties was explored for semiconducting BaTiO3 ceramics. The role of chemical reactivity at the interface was quantified through sessile drop measurements of the work of adhesion (W-ad). The interfacial properties were characterized with impedance spectroscopy to quantify contact resistance and capacitance. It was observed that interfaces with a strong chemical interaction between the metal and the oxygen anion in the ceramic showed large W-ad and correspondingly low contact resistances. It is believed that an oxygen depleted region near the surface of the BaTiO3 was formed as a result of the strong metal-oxygen interactions and led to a large W-ad and an Ohmic contact. (C) 2001 Kluwer Academic Publishers.