Varistor properties of ZnO/Pr{sub}6O{sub}11 multilayered composites prepared by pulsed laser ablation method

摘要

ZnO-Pr{sub}6O{sub}11 varistors exhibit non-ohmic current-voltage characteristics due to the double Schottky barrier formed at the interface between ZnO grains and intergranular phases of Pr{sub}6O{sub}11 . In this paper, the I-V characteristic ofZnO/ Pr{sub}6O{sub}11 multilayerd films with different thickness fabricated by pulsed laser ablation method are studied. In spite of decreasing the film thickness, the films with 5000~500A thickness exhibit nonlinear I-V characteristic. The values ofbreakdown voltage (V{sub}b) and non-linear coefficient (α) are estimated as V{sub}b=0.19-0.30V, α=2.5~4.1. Therefore. thin ZnO/Pr{sub}6O{sub}11 multilayered films prepared by PLD method show lower breakdown voltage.