| Summary: | 碩士 === 國立中興大學 === 電機工程學系 === 90 === Abstract
The AxSr1-xBi2Ta2O9 (A = Ba, Ca; X = 0.2,0.4~1.0) were synthesized by solid-state reaction sintering method. The structures and lattice constant of those crystallizations were refined by X-ray powder diffraction. Effect of ionic radius for crystallizations shows great influences on dielectric, ferroelectric and piezoelectric properties. The BaxSr1-xBi2Ta2O9 with x > 0.2 show the large dielectric constant (er’) at room temperature and low Curie temperature (Tc). The CaxSr1-xBi2Ta2O9 with x > 0.4 show that the Curie temperature over 580. The hysteresis loop could be found in CaxSr1-xBi2Ta2O9 with x = 0.0, 0.2 ~ 1.0 at room temperature. For BaxSr1-xBi2Ta2O9 with x = 0.0, 0.2 and 0.4 the hysteresis loop could be observed at room temperature. But it is not apparent with x > 0.4. Piezoelectric properties and piezoelectric parameter (kt, kp) were also found.
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