中国物理B ›› 2007, Vol. 16 ›› Issue (6): 1780-1785.doi: 10.1088/1009-1963/16/6/051
朱振业1, 王海1, 郑跃1, 李青坤1, 王彪2
Zhu Zhen-Ye(朱振业)a), Wang Biao(王彪)a)b)† , Wang Hai(王海)a), Zheng Yue(郑跃)a), and Li Qing-Kun(李青坤)a)
摘要: We have performed the first-principles calculation to investigate the origins of ferroelectricities and different polarization behaviours of superlattices BaTiO$_{3}$/SrTiO$_{3}$ and PbTiO$_{3}$/SrTiO$_{3}$. The density of state (DOS) and electronic charge profiles show that there are strong hybridizations between atoms Ti and O and between atoms Pb and O which play very important roles in producing the ferroelectricities of superlattices BaTiO$_{3}$/SrTiO$_{3}$ and PbTiO$_{3}$/SrTiO$_{3}$. Owing to the decline of internal electric field in SrTiO$_{3}$ (ST) layer, the tetragonality and polarizations of superlattices decrease with increasing the fraction of SrTiO$_{3}$ in the superlattices. We find that the polarization of PbTiO$_{3}$/SrTiO$_{3}$ is larger$_{ }$than that of BaTiO$_{3}$/SrTiO$_{3}$ at the same ratio of components, because the polarization mismatch between PbTiO$_{3}$ and SrTiO$_{3}$ is larger than that between BaTiO$_{3}$ and SrTiO$_{3}$. The polarization and tetragonality are enhanced with respect to those of bulk tetragonal BaTiO$_{3}$ in the superlattices BaTiO$_{3}$/SrTiO$_{3}$, while the polarization and tetragonality are reduced with respect to those of bulk tetragonal PbTiO$_{3}$ in superlattices PbTiO$_{3}$/SrTiO$_{3}$.
中图分类号: (Ferroelectricity and antiferroelectricity)