The thermochemistry and non-ohmic electrical contacts of a BaTiO₃ PTCR ceramic

In this investigation we establish a fundamental link between olectrode-semiconducting oxide adhesion characteristics and the electronic characteristics. For a number of metal electrodes, we relate the non-Ohmic contact resistance to the thermodynamic work of adhesion. The thermodynamic work of adhesion is determined from metal cation-metal atom interactions and the metal atomoxygen interactions, and compared to sessile drop wetting experiments. The non-Ohmic contacts are characterized by impedance spectroscopy methods to separate grain, grain boundary, and electrode contact resistance.