Sr_2Bi_(4-x)La_xTi_5O_(18)铁电陶瓷性能的研究

Study On the Properties of Sr_2Bi_4_xLa_xTi_5O_18 Ferroelectric Ceramics

采用固相烧结工艺制备了Sr_2Bi_4-xLaxTi_5O_18(x=0.00,0.10,0.25,0.50,0.75,1.00)陶瓷样品.用X射线衍射仪对其微结构进行了分析,并测量了其铁电、介电性能.结果表明,随着La含量的增加,样品的剩余极化P_r和矫顽场E_c逐渐减小,这是由于La掺杂使得样品晶格畸变变小,从而导致剩余极化的降低.相变温度T_c随着La含量的增加而降低,这也与样品晶格畸变有关.

Sr2Bi4_xLaxTi5Ol8 ferroelectric ceramic samples of which x = 0.00, 0.10, 0.25, 0.50, 0.75, 1.00 are prepared by traditional solid - state reaction method. Their structure is analyzed by X-ray diffraction, and their ferroelectric and dielectric properties are measured. It is found that with the increasing of lanthanum content, the remnant polarization, coercive field and Curie temperature decrease. These results can be explained as follows: in the Sr2Bi4_xLaxTi5O18 system, the substitution of larger ion radius La for A - site Bi atoms in the pseudo - perovskite blocks, leads to less structural distortion, resulting in smaller 2Pr and lower Tc