Bi-O covalency in PbTiO3-BiInO3 with enhanced ferroelectric properties: Synchrotron radiation diffraction and first-principles study

作者：Wang, Fangfang; Fan, Longlong; Ren, Yang; Chen, Jun^*; Xing, Xianran

来源：Applied Physics Letters, 2014, 104(25): 252901.

DOI：10.1063/1.4881614

• PHASE-BOUNDARY
• PIEZOELECTRICS

High-T-C ferroelectric (1 - x) PbTiO3-xBiInO(3) shows a sustainable spontaneous polarization in tetragonal phase by amount of BiInO3 augmented. It is rare and interesting that weak ferroelectric In3+ substitution does not reduce ferroelectricity as most of BiMeO3 materials. To understand this abnormality behavior, the structure and the cation displacements are studied by means of synchrotron radiation diffraction. The cation displacements of A-site atoms and B-site atoms exhibit a coupling property. Their sustainedly increasing trend is quantitatively associated with spontaneous polarization. Moreover, the structure, the valence electron density distributions, electron localization function, and Bader analysis have been researched on the chemical bond in (1 - x) PbTiO3-xBiInO(3) through first-principles calculations here. Although In atoms substitution reduces the covalency degree, this loss is offset by enhanced covalency between Bi-O bonds. The crucial role of Bi atom substitution not only contributes to enhance the covalency but also promotes the polarization.

• 出版日期2014-6-23
• 单位北京科技大学