Structure and properties of La-modified Na0.5Bi0.5TiO3 at ambient and elevated temperatures

摘要: The crystal structure and property changes of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) piezoelectric ceramics are reported as a function La modification (0.5–2.0 at. %) increasing temperature using high resolution x-ray diffraction, permittivity, depolarization, polarization strain hysteresis measurements. substitution is found to decrease the depolarization NBT (e.g., 1.5 % lowers by 60 °C relative unmodified composition) with little impact on room hysteresis. structures various compositions were modeled mixture monoclinic Cc space group cubic Pm3¯m phase, where phase used model local regions in material which do not obey long range group. With substitution, lattice parameter distortions associated approached that prototypical unit cell...