Electrical properties and application stability of the effects of La2O3 doping RuO2-CuO based resistive pastes with near-linear positive TCR

This study investigates the electrical properties and stability of resistor pastes formulated from RuO 2 –CuO composites doped with La 2 O 3 . The pastes exhibit an approximately linear positive temperature coefficient (PTC) of resistance behavior, referred to as near-linear positive temperature coefficient of resistance (TCR) in this work, to emphasize the linearity of the resistance-temperature relationship, with optimal performance achieved at 1.2 wt% La 2 O 3 doping. Microstructural analyses indicate that La 2 O 3 promotes densification of the resistive layer, enhancing the stability of the conductive network. After 1000 h of storage at room temperature, the resistance change rate is approximately 0.5%. Under high-temperature conditions (150 °C for 240 h), the rate increases slightly to about 2%, demonstrating satisfactory preliminary stability.