The dependence of the ferroelectric and piezoelectric properties of (1- x)(0.33BaTiO 3-0.67BiFeO 3)-xBi(Mg 1/2Ti 1/2)O 3 (x= 0, 0.05, 0.10, and 0.15) on Bi(Mg 1/2Ti 1/2)O 3 content x associated with microstructural changes is studied. From the behaviour of electric field-induced polarization and strain, polarization switching and depolarizing become easier as Bi(Mg 1/2Ti 1/2)O 3 content x increases. Remanent polarization and dielectric constant decrease, while polarization saturation field increases with increasing x. Microstructural observation reveals that Bi(Mg 1/2Ti 1/2)O 3 addition enhances the compositional fluctuation of BaTiO 3/BiFeO 3 ratio, which probably creates a nanometre-sized domain region with slightly BaTiO 3-rich composition. Since this nanometre-sized domain may cause relatively large responses of polarization and strain to the applied electric field, an appropriate amount of Bi(Mg 1/2Ti 1/2)O 3 enhances the electric field-induced strain, resulting in the largest piezoelectric response at x = 0:05. However, excessive Bi(Mg 1/2Ti 1/2)O 3 degrades polarization and strain characteristics, because a number of Ba(Fe1x - Mgx=2Tix=2)12O19 grains are created as a secondary phase and cause the segregation of excess bismuth oxide phases with low dielectric constant into the boundaries of the ferroelectric/piezoelectric grains.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)