Polar octahedral rotations: A path to new multifunctional materials

Benedek, Nicole A.; Mulder, Andrew T.; Fennie, Craig J.

doi:10.1016/j.jssc.2012.04.012

Cited by 224 publications

(255 citation statements)

References 68 publications

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“…This additional X + 5 542 mode is also found in P nma of ABO 3 perovskites [83,84] to similar antipolar motions but of oxygen instead of the A site 546 (see Fig. 4).…”

supporting

confidence: 57%

First-principles reinvestigation of bulk WO3

et al. 2016

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6Using first-principles calculations, we analyze the structural properties of tungsten trioxide WO 3 . Our calculations rely on density functional theory and the use of the B1-WC hybrid functional, which provides very good agreement with experimental data. We show that the hypothetical high-symmetry cubic reference structure combines several ferroelectric and antiferrodistortive (antipolar cation motions, rotations, and tilts of oxygen octahedra) structural instabilities. Although the ferroelectric instability is the largest, the instability related to antipolar W motions combines with those associated to oxygen rotations and tilts to produce the biggest energy reduction, yielding a P 2 1 /c ground state. This nonpolar P 2 1 /c phase is only different from the experimentally reported P c ground state by the absence of a very tiny additional ferroelectric distortion. The calculations performed on a stoichiometric compound so suggest that the low-temperature phase of WO 3 is not intrinsically ferroelectric and that the experimentally observed ferroelectric character might arise from extrinsic defects such as oxygen vacancies. Independently, we also identify never observed R3m and R3c ferroelectric metastable phases with large polarizations and low energies close to the P 2 1 /c ground state, which makes WO 3 a potential antiferroelectric material. The relative stability of various phases is discussed in terms of the anharmonic couplings between different structural distortions, highlighting a very complex interplay.

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“…This additional X + 5 542 mode is also found in P nma of ABO 3 perovskites [83,84] to similar antipolar motions but of oxygen instead of the A site 546 (see Fig. 4).…”

supporting

confidence: 57%

First-principles reinvestigation of bulk WO3

et al. 2016

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“…The layered cation ordering in the 1:1 superlattice lowers the cubic symmetry of the ideal perovskite structure to tetragonal P 4/mmm (#123). A coriented oxygen octahedron rotation pattern, combined with the layered cation ordering, produces a P mb2 1 (#26) structure with a small in-plane electric polarization resulting from non-cancellation of alternating A and A in-plane displacements [11,29]; the computed value for the systems considered here is close to 4 µC/cm 2 (see supplementary material). A CCO charge ordering pattern lowers the symmetry further.…”

Section: And Vmentioning

confidence: 71%

Charge-Order-Induced Ferroelectricity inLaVO3/SrVO3Superlattices

2017

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The structure and properties of the 1:1 superlattice of LaVO3 and SrVO3 are investigated with a firstprinciples density-functional-theory-plus-U (DFT+U ) method. The lowest energy states are antiferromagnetic charge-ordered Mott-insulating phases. In one of these insulating phases, layered charge ordering combines with the layered cation ordering to produce a polar structure with nonzero spontaneous polarization normal to the interfaces. This polarization is produced by electron transfer between the V 3+ and V 4+ layers, and is comparable to that of conventional ferroelectrics. The energy of this polar state relative to the nonpolar ground state is only 3 meV per vanadium. Under tensile strain, this energy difference can be further reduced, suggesting that the polar phase can be induced by applied electric field, yielding an antiferroelectric double-hysteresis loop. If the system does not switch back to the nonpolar state on removal of the field, a ferroelectric-type hysteresis loop could be observed. PACS numbers: 73.21.Cd, 75.25.Dk, 77.55.Px The investigation of novel mechanisms for ferroelectricity has attracted much interest in recent years, especially in the search for ferroelectrics with properties, such as ferromagnetism, that are contraindicated by the mechanism driving ferroelectricity in the prototypical perovskite titanates [1]. One approach, proposed by Khomskii [2,3] is to combine two symmetry-breaking orderings, neither of which separately lift inversion symmetry, to generate a switchable polar structure [4]. The specific orderings discussed by Khomskii are sitecentered charge ordering and bond-centered charge ordering. Ferroelectricity and multiferroelectricity induced by charge order have been proposed and reported in various magnetites, manganates, and charge transfer organic salts [2,3,5]. In some of these materials, the polarization is dominated by the electron transfer producing the charge order rather than by ionic displacements, leading to the term "electronic ferroelectricity." [6][7][8] In perovskite transition metal (TM) oxide (ABO 3 ) n (A BO 3 ) m (001) superlattices, the layered cation ordering lowers the symmetry from cubic to tetragonal and breaks up-down symmetry across BO 2 layers. Control of the TM d-orbital occupancy through choice of A cations and layer thicknesses to obtain a mixed valence leads to charge disproportionation and long-range charge ordering [9-12]. As we will discuss further below, layered charge ordering breaks the up-down symmetry across the AO and A O layers. Thus, the combination of these two symmetry-breaking orderings (TM site-centered charge ordering and layered cation ordering) can generate a switchable polar structure with polarization normal to the layers.A 1:1 superlattice composed of LaVO 3 and SrVO 3 is a promising candidate for this type of charge-order-induced ferroelectricity. The low temperature phases of orthorhombic LaVO 3 and cubic SrVO 3 are antiferromagnetic Mottinsulating and correlated metallic, respectively [9,[13][14][15]. When they f...

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“…Proposed improper mechanisms based on electronic degrees of freedom include magnetic cycloidal order, 6 charge ordering, 7 and spin-Peierls distortions. More recently several (hybrid) improper ferroelectric mechanisms have been proposed that rely on lattice anharmonicities between two or more displacive modes (Q) of the crystal, [9][10][11][12] Useful anharmonicities in the free energy potential are of the form λP n Q m , λP n Q m 1 Q 2 , . .…”

mentioning

confidence: 99%

Ferroelectricity from coupled cooperative Jahn-Teller distortions and octahedral rotations in ordered Ruddlesden-Popper manganates

Cammarata

Rondinelli

2015

Phys. Rev. B

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Density functional theory and group theoretical methods are used to explore the origin for ferroelectricity in cation ordered LaSrMnO4 with the Ruddlesden-Popper structure. The equilibrium phase exhibits the polar, P ca21 space group, where small polar displacements of d 4 Mn 3+ coexist with antiferrodistortive octahedral rotations and Jahn-Teller distortions. We find that the octahedral rotations and Jahn-Teller distortion stabilize the polar structure and induce polar displacements through high-order anharmonic interactions among the three modes, making LaSrMnO4 a hybridimproper ferroelectric material. The rotations result from the ionic size mismatch between the A cations and Mn whereas the Jahn-Teller distortions are energetically favored owing to the coupling between the local eg orbital polarization of the two nearest neighboring Mn cations in the two dimensional MnO2 sheets. Our results indicate that anharmonic interactions among multiple centric modes can be activated by cation ordering to induce polar displacements in layered oxides, making it a reliable approach for realizing acentric responses in artificially constructed materials.

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Polar octahedral rotations: A path to new multifunctional materials

Cited by 224 publications

References 68 publications

First-principles reinvestigation of bulk WO3

First-principles reinvestigation of bulk WO3

Charge-Order-Induced Ferroelectricity inLaVO3/SrVO3Superlattices

Ferroelectricity from coupled cooperative Jahn-Teller distortions and octahedral rotations in ordered Ruddlesden-Popper manganates

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