Papers by Keyword: Ba(Ti,Zr)O₃

Abstract: In order to prepare lead free multi-layer ceramic (MLC) actuators with Ni inner electrodes, inkjet ink containing NiO was prepared and its rheological properties were examined. The viscosity of the ink followed the Andrade's equation. By using this ink, Ba(Ti,Zr)O3 based MLCs were prepared. The printed NiO layers were reduced to metal Ni and they functioned as the inner electrodes. The remanent polarization of the MLCs increased with the grain growth caused by the increase of firing temperature. The remanent polarization Pr and coercive field Ec of the MLCs fired at 1400°C were 6.4 μC/cm2 and 3.5 kV/cm, respectively. The displacement of the MLCs with 7 active layers was approximately 320nm at 30 kV/cm. The effective d33 shows approximately 160 pm/V when the electric field was 10 kV/cm.

Abstract: In this paper, the influence of nickel (Ni) nano-powders addition on the microstructures and dielectric properties of Ba(Ti,Zr)O3 based Y5V non-reducing ceramics were investigated. The X-ray diffraction (XRD) analysis indicated that the primary phase was Ba(Ti,Zr)O3 and no Ni phase appeared until the amount of Ni exceeded 5mol%. Scanning electron microscope (SEM) observation showed that the Ni particles distributed homogenously throughout BTZ ceramic matrix. The incorporation of Ni altered the perovskite lattice parameters and thus led to the change of polarization degree under electric field and the improvement of the dielectric constant at Curie temperature.

Abstract: [BaO]m(Ti0.975Zr0.025)O2 ceramics with Ni electrodes were prepared by a firing in N2 atmosphere. The dielectric, ferroelectric and piezoelectric properties were examined in terms of the composition. The remanent polarization of 9.5μC/cm2 was obtained for m=1.01 by the addition of 0.5wt% SiO2. The longitudinal piezoelectric constant d33 calculated from a unipolar signal (8kV/cm,10Hz) was 430pC/N. Lead-free multi-layered piezoelectric actuators were fabricated using this material by the tape casting, screen-printing of Ni electrodes, laminating under heat and pressure, and firing in N2 atmosphere. The displacement of the actuator with 75μm x 9 active piezoelectric layers was 0.17μm at an applied voltage of 75V and a frequency of 10Hz.