Preparation of Inkjet-Printed NiO Films for Ba(Ti,Zr)O3-Based Ceramics and Application to Multilayer Ceramics with Ni Electrodes

Abstract

The possibility of fabricating a lead-free multilayer ceramic (MLC) actuator with Ni inner electrodes prepared by inkjet printing has been investigated. Inkjet ink containing NiO powder was prepared. NiO films were prepared on [(BaO)1.00(CaO)0.01](Ti0.95Zr0.05)O2 green sheets by the inkjet method and co-fired in a reducing atmosphere. After co-firing, the NiO films were reduced to metal Ni films, which acted as electrodes. The remanent polarization Pr and coercive field Ec of the ceramics were 2.5 µC/cm2 and 3.0 kV/cm, respectively. The Curie temperature, orthorhombic–tetragonal transition temperature, and rhombohedral–orthorhombic transition temperature were 110, 45, and 0 °C, respectively. The [(BaO)1.00(CaO)0.01](Ti0.95Zr0.05)O2 MLCs with Ni inner electrodes were prepared using NiO ink. The diffusion and reaction of Ni to ceramic layers were not observed. The displacement of the MLCs with seven active layers was approximately 0.17 µm when the electric field was 20 kV/cm. It is expected that inkjet printing using NiO ink will be applicable to the fabrication of lead-free MLC actuators with Ni inner electrodes.