From first- to second-order phase transitions in hybrid improper ferroelectrics through entropy stabilization

Pomiro, Fernando; Ablitt, Chris; Bristowe, Nicholas C.; Mostofi, Arash A.; Won, Coongjae; Cheong, Sang-Wook; Senn, Mark S.

doi:10.1103/physrevb.102.014101

From first- to second-order phase transitions in hybrid improper ferroelectrics through entropy stabilization

Pomiro, Fernando; Ablitt, Chris; Bristowe, Nicholas C.; Mostofi, Arash A.; Won, Coongjae; Cheong, Sang-Wook; Senn, Mark S.

Authors

Fernando Pomiro

Chris Ablitt

Dr Nicholas Bristowe nicholas.bristowe@durham.ac.uk
Associate Professor

Arash A. Mostofi

Coongjae Won

Sang-Wook Cheong

Mark S. Senn

Abstract

Hybrid improper ferroelectrics (HIFs) have been studied intensively over the past few years to gain an understanding of their temperature-induced phase transitions and ferroelectric switching pathways. Here we report a switching from a first- to a second-order phase transition pathway for HIFs Ca3−xSrxTi2O7, which is driven by the differing entropies of the phases that we identify as being associated with the dynamic motion of octahedral tilts and rotations. A greater understanding of the transition pathways in this class of layered perovskites, which host many physical properties that are coupled to specific symmetries and octahedral rotation and tilt distortions—such as superconductivity, negative thermal expansion, fast ion conductivity, ferroelectricity, among others—is a crucial step in creating novel functional materials by design.

Citation

Pomiro, F., Ablitt, C., Bristowe, N. C., Mostofi, A. A., Won, C., Cheong, S., & Senn, M. S. (2020). From first- to second-order phase transitions in hybrid improper ferroelectrics through entropy stabilization. Physical Review B, 102(1), Article 014101. https://doi.org/10.1103/physrevb.102.014101

Journal Article Type	Article
Acceptance Date	Jun 12, 2020
Online Publication Date	Jul 7, 2020
Publication Date	2020-07
Deposit Date	Aug 4, 2020
Publicly Available Date	Aug 23, 2020
Journal	Physical Review B
Print ISSN	2469-9950
Electronic ISSN	2469-9969
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	102
Issue	1
Article Number	014101
DOI	https://doi.org/10.1103/physrevb.102.014101

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