Title: Superlattice-induced ferroelectricity in charge-ordered La _1/3 Sr _2/3 FeO ₃

Abstract

Charge-order–driven ferroelectrics are an emerging class of functional materials, distinct from conventional ferroelectrics, where electron-dominated switching can occur at high frequency. Despite their promise, only a few systems exhibiting this behavior have been experimentally realized thus far, motivating the need for new materials. Here, we use density-functional theory to study the effect of artificial structuring on mixed-valence solid-solution La _1/3 Sr _2/3 FeO ₃ (LSFO), a system well studied experimentally. Our calculations show that A-site cation (111)-layered LSFO exhibits a ferroelectric charge-ordered phase in which inversion symmetry is broken by changing the registry of the charge order with respect to the superlattice layering. The phase is energetically degenerate with a ground-state centrosymmetric phase, and the computed switching polarization is 39 μC/ ${\mathrm{c}\mathrm{m}}^2$ , a significant value arising from electron transfer between ${\mathrm{F}\mathrm{e}\mathrm{O}}_6$ octahedra. Our calculations reveal that artificial structuring of LSFO and other mixed valence oxides with robust charge ordering in the solid solution phase can lead to charge-order–induced ferroelectricity.

Authors:

Park, Se Young; Rabe, Karin M.; Neaton, Jeffrey B.

Publication Date:

2019-11-11

Sponsoring Org.:

USDOE

OSTI Identifier:

1574027

Grant/Contract Number:  

AC02-05-CH11231: Materials Project program KC23MP

Resource Type:

Published Article

Journal Name:

Proceedings of the National Academy of Sciences of the United States of America

Additional Journal Information:

Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Volume: 116 Journal Issue: 48; Journal ID: ISSN 0027-8424

Publisher:

Proceedings of the National Academy of Sciences

Country of Publication:

United States

Language:

English