Microstructural, structural and electrical properties of La~(3+)-modified ferroelectric ceramics

摘要

Bi_(4-x)La_xTi_3O_(12) (BLT) ceramics were prepared and studied in this work in terms of La~(3+)-modified microstructure and phase development as well as electrical response. According to the results processed from X-ray diffraction and electrical measurements, the solubility limit (x_L) of La~(3+) into the Bi_4Ti_3O_12 (BIT) matrix was here found to locate slightly above x= 1.5. Further, La~(3+) had the effect of reducing the material grain size, while changing its morphology from the plate-like form, typical of BIT ceramics, to a spherical-like one. The electrical results presented and discussed here also include the behavior of the temperature of the ferroelectric-paraelectric phase transition as well as the normal or diffuse and/or relaxor nature of this transition depending on the La~(3+) content.