TY - JOUR
T1 - Ferroelectric Sr3Zr2O7
T2 - Competition between Hybrid Improper Ferroelectric and Antiferroelectric Mechanisms
AU - Yoshida, Suguru
AU - Fujita, Koji
AU - Akamatsu, Hirofumi
AU - Hernandez, Olivier
AU - Sen Gupta, Arnab
AU - Brown, Forrest G.
AU - Padmanabhan, Haricharan
AU - Gibbs, Alexandra S.
AU - Kuge, Toshihiro
AU - Tsuji, Ryosuke
AU - Murai, Shunsuke
AU - Rondinelli, James M.
AU - Gopalan, Venkatraman
AU - Tanaka, Katsuhisa
N1 - Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/7/25
Y1 - 2018/7/25
N2 - In contrast to polar cation displacements driving oxides into noncentrosymmetric and ferroelectric states, inversion-preserving anion displacements, such as rotations or tilts of oxygen octahedra about cation coordination centers, are exceedingly common. More than one nonpolar rotational mode in layered perovskites can lift inversion symmetry and combine to induce an electric polarization through a hybrid improper ferroelectric (HIF) mechanism. This form of ferroelectricity expands the compositional palette to new ferroelectric oxides because its activity derives from geometric rather than electronic origins. Here, the new Ruddlesden–Popper HIF Sr3Zr2O7, which is the first ternary lead-free zirconate ferroelectric, is reported and room-temperature polarization switching is demonstrated. This compound undergoes a first-order ferroelectric-to-paraelectric transition, involving an unusual change in the “sense” of octahedral rotation while the octahedral tilt remains unchanged. Our experimental and first-principles study shows that the paraelectric polymorph competes with the polar phase and emerges from a trilinear coupling of rotation and tilt modes interacting with an antipolar mode. This form of hybrid improper “antiferroelectricity” is recently predicted theoretically but has remained undetected. This work establishes the importance of understanding anharmonic interactions among lattice degrees of freedom, which is important for the discovery of new ferroelectrics and likely to influence the design of next-generation thermoelectrics.
AB - In contrast to polar cation displacements driving oxides into noncentrosymmetric and ferroelectric states, inversion-preserving anion displacements, such as rotations or tilts of oxygen octahedra about cation coordination centers, are exceedingly common. More than one nonpolar rotational mode in layered perovskites can lift inversion symmetry and combine to induce an electric polarization through a hybrid improper ferroelectric (HIF) mechanism. This form of ferroelectricity expands the compositional palette to new ferroelectric oxides because its activity derives from geometric rather than electronic origins. Here, the new Ruddlesden–Popper HIF Sr3Zr2O7, which is the first ternary lead-free zirconate ferroelectric, is reported and room-temperature polarization switching is demonstrated. This compound undergoes a first-order ferroelectric-to-paraelectric transition, involving an unusual change in the “sense” of octahedral rotation while the octahedral tilt remains unchanged. Our experimental and first-principles study shows that the paraelectric polymorph competes with the polar phase and emerges from a trilinear coupling of rotation and tilt modes interacting with an antipolar mode. This form of hybrid improper “antiferroelectricity” is recently predicted theoretically but has remained undetected. This work establishes the importance of understanding anharmonic interactions among lattice degrees of freedom, which is important for the discovery of new ferroelectrics and likely to influence the design of next-generation thermoelectrics.
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U2 - 10.1002/adfm.201801856
DO - 10.1002/adfm.201801856
M3 - Article
AN - SCOPUS:85047660352
SN - 1616-301X
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 30
M1 - 1801856
ER -