Structural and Electrical Properties of Lanthanide substituted-Bismuth Titanate Prepared by Low-Temperature Combustion Synthesis

摘要

This paper elucidates the structural and electrical properties of Bi_4Ti_3O_(12) (BIT), Bi_(3.25)Nd_(0.75)Ti_3O_(12) (BNT075) and Bi_(3.25)La_(0.75)Ti_3O_(12) (BLT075) compounds that were primarily prepared by a novel combustion route at temperature as low as 300°C. Single crystalline phase of bismuth-layered perovskite structure was obtained directly after combustion without calcination. X-ray diffraction and Raman spectra analysis showed the phase transition from orthorhombic to tetragonal symmetry with substituting compounds. Compared to BIT, the Curie temperature at maximum dielectric peak of BNT075 and BLT075 decreased to lower values of 434°C and 365°C, respectively. The loss tangen for corresponding substitution compounds were 5 times lower than that of BIT. Besides, BNT075 resulted in large remanent polarization (2P_r) and coercive field (E_c) values of 19μC/cm~2 and 45 kV/cm, respectively, while 17.6μC/cm~2 and 42 kV/cm for BLT075.