title: Why Sn doping significantly enhances the dielectric properties of Ba(Ti 1-x Snx)O3.
abstract: Through appropriate doping, the properties of BaTiO3-based ferroelectrics can be significantly enhanced. To determine the physical process induced by the doping of Sn atoms in Ba(Ti0.8Sn0.2)O3, we performed high-resolution scanning transmission electron microscopy experiments and observed that the regions with low Sn content formed polar nano regions (PNRs) embedded in the matrix in Ba(Ti0.8Sn0.2)O3. The interactions among Sn, Ti, Ba and O atoms were determined using first principles calculations. Based on the characteristics of the electronic structure and crystal lattice strain fields, the effects of doping with Sn were investigated. The Sn doping not only changed the electronic structure of the crystal but also increased the dielectric properties of the PNRs. Moreover, the Sn doping was also responsible for the diffuse phase transition of the Ba(Ti 1-x Snx)O3 material. The effects mentioned in this paper are universal in lead-free ferroelectrics, and similar elements such as Sb, Mg, and Zr may have the same functions in other systems. Thus, these results provide guidance for the design of the doping process and new systems of ferroelectric or relaxor materials.
authors.affiliation: National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shi
authors.affiliation: National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xie
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
authors.affiliation: National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu