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The origin of hyperferroelectricity in LiBO3 (B?=?V, Nb, Ta, Os).

ABSTRACT: The electronic and structural properties of LiBO3 (B?=?V, Nb, Ta, Os) are investigated via first-principles methods. We show that LiBO3 belong to the recently proposed hyperferroelectrics (hyperFEs), i.e., they all have unstable longitudinal optic phonon modes. Especially, the ferroelectric-like instability in the metal LiOsO3, whose optical dielectric constant goes to infinity, is a limiting case of hyperFEs. Via an effective Hamiltonian, we further show that, in contrast to normal proper ferroelectricity, in which the ferroelectric instability usually comes from long-range coulomb interactions, the hyperFE instability is due to the structure instability driven by short-range interactions. This could happen in systems with large ion size mismatches, which therefore provides a useful guidance in searching for novel hyperFEs.

SUBMITTER: Li P

PROVIDER: S-EPMC5046123 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature

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The origin of hyperferroelectricity in LiBO3 (B = V, Nb, Ta, Os).

Li Pengfei P Ren Xinguo X Guo Guang-Can GC He Lixin L

Scientific reports 20161003

The electronic and structural properties of LiBO3 (B = V, Nb, Ta, Os) are investigated via first-principles methods. We show that LiBO3 belong to the recently proposed hyperferroelectrics (hyperFEs), i.e., they all have unstable longitudinal optic phonon modes. Especially, the ferroelectric-like instability in the metal LiOsO3, whose optical dielectric constant goes to infinity, is a limiting case of hyperFEs. Via an effective Hamiltonian, we further show that, i ...[more]

PMID: 27694996

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