title: Enhancing dielectric permittivity for energy-storage devices through tricritical phenomenon.
abstract: Although dielectric energy-storing devices are frequently used in high voltage level, the fast growing on the portable and wearable electronics have been increasing the demand on the energy-storing devices at finite electric field strength. This paper proposes an approach on enhancing energy density under low electric field through compositionally inducing tricriticality in Ba(Ti,Sn)O3ferroelectric material system with enlarged dielectric response. The optimal dielectric permittivity at tricritical point can reach to εr= 5.4 × 104, and the associated energy density goes to around 30 mJ/cm3at the electric field of 10 kV/cm, which exceeds most of the selected ferroelectric materials at the same field strength. The microstructure nature for such a tricritical behavior shows polarization inhomogeneity in nanometeric scale, which indicates a large polarizability under external electric field. Further phenomenological Landau modeling suggests that large dielectric permittivity and energy density can be ascribed to the vanishing of energy barrier for polarization altering caused by tricriticality. Our results may shed light on developing energy-storing dielectrics with large permittivity and energy density at low electric field.
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Xinghao
authors.initials: X
authors.lastname: Hu
authors.affiliation: Center of Microstructure Science, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Ke
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Lisheng
authors.initials: L
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: He
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.|Ferroic Physics Group, National Institute for Materials Science, Tsukuba, 305-0047, Ibaraki, Japan.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Ren