Electrical Characteristics and Microstructures of Gd-Doped Bi_4Ti_3O_(12) Ceramics

摘要

The electrical properties of Gd-doped bismuth titanates (Bi_(3.25)Gd_(0.75)Ti_3O_(12), BGT) prepared by a conventional ceramic technique have been investigated. At applied d.c. field below 200V/mm, the current-voltage curve of the BGT ceramic exhibits a negative differential resistance behavior. The impedance spectrum indicates that the sample consists of semiconducting grain and moderately insulating grain boundary regions. XRD, SEM and EPMA analyses reveal crystalline phase characterized by a Bi-layered perovskite structure of Bi_4Ti_3O_(12) (BIT) and the distribution of every element is uniform. The BGT sample exhibits randomly oriented and plate-like morphology.