SrBi_(2-x)Dy_xNb_2O_9无铅压电陶瓷制备及其高温稳定性研究

Preparation and High Temperature Stability of SrBi_(2-x)Dy_xNb_2O_9 Lead-free Piezoelectric Ceramics

采用固相烧结工艺制备SrBi_(2-x)Dy_xNb_2O_9(x=0,0.03,0.05,0.07)陶瓷样品,研究了Dy^(3+)掺杂量对其微观结构、电学性能及其高温稳定性的影响。结果表明,Dy^(3+)并未改变陶瓷的晶体结构,并且对样品的微观形貌影响不明显,但随着Dy^(3+)掺杂量的增加剩余极化强度(2P_r)先增大后减小,同时矫顽场(E_c)降低,居里温度(T_c)由444℃降低到427℃,这是由于Dy^(3+)的掺杂影响晶格畸变的结果。当x=0.03时,陶瓷具有较好的综合性能:2P_r=16μC/cm^2,E_c=56 kV/cm,T_c=436℃,说明该材料具有较好的铁电及温度稳定性。

SrBi2-xDyxNb2O9（x=0, 0.03, 0.05, 0.07） ceramics were prepared by solid state reaction method, and their microstructure, electrical and temperature stability properties were systematically investigated. It is found that Dy-doping does not change the phase structure of SrBi2Nb2O9. With the increasing of the Dy3＋ content, the microstructures of the SrBi2-xDyxNb2O9 ceramics have no significant change. The remnant polarization （Pr） increases firstly and then decreases, reaching the maximum value at x=0.01, while the coercive field （Eo） decreases gradually. Furthermore, the Curie temperature decreases from 444℃ to 427℃ with the increase of the Dy3＋ content. These results can be related to the lattice distortion caused by Dy-doping. The optimum electrical properties can be obtained at x=0.03 as 2Pr=16.4μC/cm2, Ec=58 kV/cm, and T0 = 436℃, showing good temperature stability for high temperature applications.