Synthesis, Structural Transformation, Thermal Stability, Valence State, and Magnetic and Electronic Properties of PbNiO<sub>3</sub> with Perovskite- and LiNbO<sub>3</sub>-Type Structures

Inaguma, Yoshiyuki; Tanaka, Kie; Tsuchiya, Takeshi; Mori, Daisuke; Katsumata, Tetsuhiro; Ohba, Tomonori; Hiraki, K.; Takahashi, Toshihiro; Saitoh, Hiroyuki

doi:10.1021/ja206247j

Cited by 107 publications

(129 citation statements)

References 65 publications

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“…Such effects are actually investigated in BiM O 3 (M = V, Cr, Mn, Fe, Co, and Ni) [20][21][22][23] and PbM O 3 (M = Ti, V, Cr, Fe, and Ni) [24,25] . These experimental results suggest that the electrons tend to be accumulated in the A(B) cations in the systems with low (high) 3d level, while they are uniformly distributed in A and B cations for the intermediate case.…”

Section: (D) the Hamiltonian Is Given Bymentioning

confidence: 99%

Theory of Valence Transition inBiNiO3

2016

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Motivated by the colossal negative thermal expansion recently found in BiNiO3, the valence transition accompanied by the charge transfer between the Bi and Ni sites is theoretically studied. We introduce an effective model for Bi-6s and Ni-3d orbitals with taking into account the valence skipping of Bi cations, and investigate the ground-state and finite-temperature phase diagrams within the mean-field approximation. We find that the valence transition is caused by commensurate locking of the electron filling in each orbital associated with charge and magnetic orderings, and the critical temperature and the nature of the transitions are strongly affected by the relative energy between the Bi and Ni levels and the effective electron-electron interaction in the Bi sites. The obtained phase diagram well explains the temperature-and pressure-driven valence transitions in BiNiO3 and the systematic variation of valence states for a series of Bi and Pb perovskite oxides. PACS numbers: 71.10.Fd , 71.30.+h , 75.25.Dk, 75.30.Kz Perovskite transition metal (TM) oxides (general formula: ABO 3 ) have been providing central issues of phase transitions and strong electron correlations in condensed matter physics [1,2]. They exhibit a wide range of novel magnetic, dielectric, and transport properties: for example, the large negative magnetoresistance in La 1−x Sr x MnO 3 [3-5], the spin-state transition in La 1−x Sr x CoO 3 [6,7], the metalto-insulator transition in RNiO 3 (R: rare earth element) [8], and the ferroelectric to quantum paraelectric transition in Ba 1−x Sr x TiO 3 [9, 10]. In these phenomena, the central players are the electrons in 3d orbitals of the B-site TMs hybridized with oxygen 2p orbitals. The A-site cations, on the other hand, are usually inert and have been regarded as "stagehands": they control the electron filling and bandwidth through their valence state and ionic radius, respectively.Peculiar exceptions to the above standards have recently been found in several perovskite TM oxides, in which the Asite cations play an active role as "valence skipper". In these compounds, not only the B-site 3d electrons but also the valence s electrons in the A-site cations significantly contribute to the electronic properties. In the valence skippers, the outermost s orbital prefers closed-shell configurations s 0 or s 2 , and tends to skip the intermediate valence s1 . This is attributed to the effective attractive interaction between s electrons [11][12][13], and hence the A-site valence state can be actively controlled through electronic degrees of freedom. Owing to the multiple electronic instabilities in both A-and B-site cations, the TM oxides with the A-site valence skipper have a potential of new electronic phases and functions.The colossal negative thermal expansion (CNTE) material BiNiO 3 [14] is one of such candidates; both Bi-6s and Ni3d electrons are expected to play a key role in the large volume change [15,16] [15,18,19]. Under pressure, this phase transition is also observed by raising temperature ...

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Section: (D) the Hamiltonian Is Given Bymentioning

confidence: 99%

Theory of Valence Transition inBiNiO3

2016

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“…The distortion from cubic perovskite is sufficiently strong that assignment of A-and B-sites is ambiguous; we have followed the assignment of Ref. [58] for PbNiO 3 , but note that treating Ni as the A-site (reversing the orientation), the Wyckoff position of oxygen becomes (0.800, 0.116, 0.384), which is slightly closer to the corresponding crystal coordinate of the other two materials. All three satisfy our requirements of low band gap, d 10 cations, and large polar distortions.…”

mentioning

confidence: 92%

“…The first has been synthesized [58], and the latter two are similar in composition to known materials. The structural parameters and bulk polarizations are given in Table I.…”

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confidence: 99%

First-Principles Materials Design of High-Performing Bulk Photovoltaics with theLiNbO3Structure

2015

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The bulk photovoltaic effect is a long-known but poorly understood phenomenon. Recently, however, the multiferroic bismuth ferrite has been observed to produce strong photovoltaic response to visible light, suggesting that the effect has been underexploited as well. Here we present three polar oxides in the LiNbO3 structure that we predict to have band gaps in the 1-2 eV range and very high bulk photovoltaic response: PbNiO3, Mg 1/2 Zn 1/2 PbO3, and LiBiO3. All three have band gaps determined by cations with d 10 s 0 electronic configurations, leading to conduction bands composed of cation s-orbitals and O p-orbitals. This both dramatically lowers the band gap and increases the bulk photovoltaic response by as much as an order of magnitude over previous materials, demonstrating the potential for high-performing bulk photovoltaics.Photovoltaic effects have long been observed in bulk polar materials, especially ferroelectrics [1][2][3][4]. Known as the bulk photovoltaic effect (BPVE), it appeared to derive from inversion symmetry breaking. Despite intense initial interest, early explorations revealed low energy conversion efficiency, in part due to the high band gaps of most known ferroelectrics. Additionally, despite several proposed mechanisms, the physical origin of the BPVE was unclear [2,[5][6][7][8].However, recent emphasis on alternative energy technologies and the observation of the effect in novel semiconducting ferroelectrics (with band-gaps in the visible range) has renewed interest [9][10][11][12][13][14]. Several studies have attempted to elucidate the various contributions to the photovoltaic response -bulk or otherwise -in ferroelectrics [15][16][17][18][19][20][21][22][23]. In particular, bismuth ferrite (BFO) has been found to generate significant bulk photocurrents; combined with its unusually low band gap of 2.7 eV, it has attracted a great deal of attention for its potential in photovoltaic applications [21,[23][24][25][26][27][28][29][30][31]. The understanding of the fundamental physics behind the effect has advanced as well; recently we demonstrated that the BPVE can be attributed to "shift currents", and that the bulk photocurrents may be calculated from first-principles. The ab initio calculation of the shift current and subsequent analysis yielded several chemical and structural criteria for optimizing the response. These criteria have been used previously to modify or identify existing materials with enhanced response [14,[32][33][34]. In this work, we use these insights to propose several candidate bulk photovoltaics with calculated response as much as an order of magnitude higher than well-known ferroelectrics, while having band gaps in or slightly below the visible spectrum. Our results demonstrate that bulk photovoltaic response can be much stronger than previously observed, supporting the possibility of materials suitable for application.There are two figures of merit for evaluating the BPVE in a material: the current density response to a spatially uniform electric field, and the G...

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“…Recently, it has been also proposed that BiMnO 3 could behave as an improper ferroelectric, where ferroelectricity could develop from a specific antiferromagnetic ordering which would break the inversion symmetry even in a centrosymmetric crystal structure [52,53]. On the other hand, a similar mechanism has been suggested to be at play in the relatively new multiferroic PbNiO 3 [54,55,56,57], despite the fact that the nominal valence of Pb is 4+, thus no lone pairs should be active on A-ions; DFT-based results have however clarified that the Pb formal valence is perturbed by Pb 6s -O 2p hybridization which results in enhanced ferroelectric instability and predicted large polarization (P ∼ 100µC/cm 2 ). …”

Section: Ferroelectricity Due To Lone Pairsmentioning

confidence: 99%

Mechanisms and origin of multiferroicity

Barone

Picozzi

2015

Comptes Rendus. Physique

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Motivated by the potential applications of their intrinsic cross-coupling properties, the interest in multiferroic materials has constantly increased recently, leading to significant experimental and theoretical advancements. From the theoretical point of view, recent progresses have allowed to identify different mechanisms responsible for the appearence of ferroelectric polarization coexisting with -and coupled to -magnetic properties. This chapter aims at reviewing the fundamental mechanisms devised so far, mainly in transition-metal oxides, which lie at the origin of multiferroicity.

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Synthesis, Structural Transformation, Thermal Stability, Valence State, and Magnetic and Electronic Properties of PbNiO₃ with Perovskite- and LiNbO₃-Type Structures

Cited by 107 publications

References 65 publications

Theory of Valence Transition inBiNiO3

Theory of Valence Transition inBiNiO3

First-Principles Materials Design of High-Performing Bulk Photovoltaics with theLiNbO3Structure

Mechanisms and origin of multiferroicity

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Synthesis, Structural Transformation, Thermal Stability, Valence State, and Magnetic and Electronic Properties of PbNiO3 with Perovskite- and LiNbO3-Type Structures

Cited by 107 publications

References 65 publications

Theory of Valence Transition inBiNiO3

Theory of Valence Transition inBiNiO3

First-Principles Materials Design of High-Performing Bulk Photovoltaics with theLiNbO3Structure

Mechanisms and origin of multiferroicity

Contact Info

Product

Resources

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Synthesis, Structural Transformation, Thermal Stability, Valence State, and Magnetic and Electronic Properties of PbNiO₃ with Perovskite- and LiNbO₃-Type Structures