Ca含量对Sr_(1-x)Ca_xBi_2Nb_2O_9无铅压电陶瓷结构与电性能的影响研究

EFFECT OF CA ON STRUCTURE AND ELECTRICAL PROPERTIES OF Sr_(1-x)Ca_xBi_2Nb_2O_9 LEAD-FREE PIEZOELECTRIC CERAMICS

采用传统固相法成功制备了Sr1-xCaxBi2Nb2O9(SCBN,x=0～0.2mol)无铅压电陶瓷,采用XRD,SEM,HP4294A等测试分析手段研究了陶瓷的晶体结构,介电、压电和铁电性能,结果表明:随着Ca取代量的增加,晶格常数逐渐减小,介电常数、压电常数以及材料的矫顽电场和剩余极化强度均有所降低,而居里温度先增大后减小,在x=0.15时,居里温度达到最大值Tc=508℃,高于纯SrBi2Nb2O9陶瓷的居里温度。

Lead-free piezoelectric ceramic of Sr1-xCaxBi2Nb2O9（SCBN,x=0～0.2） were fabricated successfully by conventional ceramics preparation technique.The crystal structure,microstructure,dielectric,piezoelectric and ferroelectric properties were detected by means of XRD,SEM and HP4294A Meters.The results show that with the increasing of Ca content,the size of crystal cell,dielectric constant,piezoelectric constant,coercive field and remanent polarization decrease.However,the Curie temperature of the system ceramics first increases then decreases,and it achieves up to the maximum 508℃ at the Ca content of x=0.15,which is higher than that of pure SrBi2Nb2O9 ceramic.