晶粒尺寸效应对极化BaTiO3陶瓷的介电压电物性的影响.doc

晶粒尺寸效应对极化BaTiO3陶瓷的介电压电物性的影响 晶粒尺寸效应对极化BaTiO3陶瓷的介电压电物性的影 响 Grain-Size Effects on Dielectric and Piezoelectric Properties of Poled BaTiO3 Ceramics ZHANG Jialiang ZHENG Peng TAN Yongqiang WANG Chunlei 5 10 15 20 25 30 35 40 School of physics State Key Laboratory of Crystal Materials Shandong University JiNan 250100 Abstract Barium titanate BaTiO3 is known historically as the first ceramic piezoelectric material and shows the high possibility to be revitalized as a popular lead-free piezoelectric material However systematical studies about the grain-size effects on the dielectric and piezoelectric properties of poled BaTiO3 ceramics have been rarely carried out so far In this work a series of dense BaTiO3 ceramics with uniform grain- size distribution were successfully prepared by the conventional solid-state reaction and the grain-size effects on the dielectric and piezoelectric properties were explored in their poled states An interesting physical phenomenon that dielectric permittivity ε and the piezoelectric constant d33 increase significantly at room temperature with the reduction of the average grain size g and reach the ima at g 094 μm has been found It was revealed that domain structure and relative density play the substantial roles in determining the ε and d33 behaviors The average 90?-domain width decreases monotonically with g Both the 90?-domain wall density and the area dimension of domain wall are considered as the important factors that greatly influence the d33 value Keywords Poled BaTiO3 ceramics Piezoelectric property Grain-size effect Domain Structure 0 Introduction Barium titanate is one of the most basic and wildly applied ferroelectric oxide materials with the perovskite-type crystalline structure With decreasing the temperature it undergoes three successive phase transitions from a cubic phase to a tetragonal phase then to an orthorhombic phase and finally to a rhombohedral phase The cubic phase is paraelectric and the