ZnOバリスタの粒界と課電劣化の関係

抄録

The effect of electrical degradation characteristics and microstructure of Sb₂O₃-added-ZnO varistors were investigated by FE-SEM, energy dispersion X-ray spectroscopy (EDX), optical microscope, X-ray diffraction (XRD), and voltage-current (V-I) characteristics. The nonlinearity index α of V-I characteristic for the Bi-Mn-Co-Sb₂O₃-added ZnO varistors decreased with increasing amount of Sb₂O₃ after the electrical degradation. The twin crystal of ZnO was formed by the addition of Sb₂O₃. The number of twin crystal, of which two c-axes are perpendicular to twin plane, increased and the number of twin crystal, of which two c-axes are parallel to twin plane, decreased with increasing the amount of addition of Sb₂O₃. It is suggested that electrical degradation is affected by combination of orientation of ZnO grains containing twin planes and double Schottky barrier may be not formed in the twin plane.