Abnormal piezoelectric and dielectric behavior of 0.92Na(0.5)Bi(0.5)TiO(3)-0.08BaTiO(3) induced by La doping

作者：Liu Liying^*; Zhu Mankang; Hou Yudong; Yan Hui; Liu Riping

来源：Journal of Materials Research, 2007, 22(5): 1188-1192.

DOI：10.1557/JMR.2007.0173

Properties and phase structures of lead-free piezoelectric ceramics 0.92Na(0.5)Bi(0.5)TiO(3)-0.08BaTiO(3) (NBT-BT) modified with La(2)O(3) have been studied. Because of the different valence and ionic radius between La(3+) and the exchangeable A-site ions, the lattice distortion and arrangement in the modified compounds can be expected, which will directly influence the phase composition and electrical characteristics of NBT-BT. Differing from familiar frame of gradual variability going with adulteration, NBT-BT doping 0.2-1.0 at.% La(2)O(3) presents an abnormal increase of dielectric constant and a dramatic vanish of piezoelectricity. Further study on the relaxor property and domain structure implies that it originates from a typical relaxor-to-antiferroelectric crossover phase transition. However, a larger addition of La(2)O(3) could rejuvenate the ferroelectricity and piezoelectricity of NBT-BT, correlating well with the model of competing ferro- and antiferroelectric interactions and metastable intermediate phase behavior in the morphotropic phase boundary region of complex perovskites.

• 出版日期2007-5
• 单位燕山大学; 北京大学; 北京工业大学