Metallic and Nonmetallic Behavior in Transition Metal Oxides

Austin, I. G.; Mott, N. F.

doi:10.1126/science.168.3927.71

Cited by 112 publications

(68 citation statements)

References 28 publications

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“…charge stripe | charge order | nickelate | strongly correlated materials | transition metal oxides C ompetition between localized and itinerant electron behavior is an organizing construct in our understanding of correlated electron transition metal oxide (TMO) physics (1)(2)(3)(4). Some of the most compelling phenomenology in these materials occurs in the mixed valent state for the transition metal, which is set by composition, doping, and anion coordination of the metal.…”

mentioning

confidence: 99%

Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈

Zhang

Chen

Phelan

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

100

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The quasi-2D nickelate La 4 Ni 3 O 8 (La-438), consisting of trilayer networks of square planar Ni ions, is a member of the so-called T′ family, which is derived from the Ruddlesden-Popper (R-P) parent compound La 4 Ni 3 O 10−x by removing two oxygen atoms and rearranging the rock salt layers to fluorite-type layers. Although previous studies on polycrystalline samples have identified a 105-K phase transition with a pronounced electronic and magnetic response but weak lattice character, no consensus on the origin of this transition has been reached. Here, we show using synchrotron X-ray diffraction on high-pO 2 floating zone-grown single crystals that this transition is associated with a real space ordering of charge into a quasi-2D charge stripe ground state. The charge stripe superlattice propagation vector, q = (2/3, 0, 1), corresponds with that found in the related 1/3-hole doped single-layer R-P nickelate, La 5/3 Sr 1/3 NiO 4 (LSNO-1/3; Ni 2.33+ ), with orientation at 45°to the Ni-O bonds. The charge stripes in La-438 are weakly correlated along c to form a staggered ABAB stacking that reduces the Coulomb repulsion among the stripes. Surprisingly, however, we find that the charge stripes within each trilayer of La-438 are stacked in phase from one layer to the next, at odds with any simple Coulomb repulsion argument.charge stripe | charge order | nickelate | strongly correlated materials | transition metal oxides C ompetition between localized and itinerant electron behavior is an organizing construct in our understanding of correlated electron transition metal oxide (TMO) physics (1-4). Some of the most compelling phenomenology in these materials occurs in the mixed valent state for the transition metal, which is set by composition, doping, and anion coordination of the metal. Many mixed valent TMOs adopt insulating "charge ordered" states, in which an inhomogeneous but long-range ordered configuration of the charge density condenses from a uniform metallic state (5). The real space pattern of charge order varies by material (6-9), but a typically observed motif is some variety of charge stripes. Such stripes have been observed in cobaltites (10-12), cuprates (13-15), nickelates (16)(17)(18)(19), and manganites (20-22), albeit with highly materials-dependent configurations that hinge on a balance among Coulomb, lattice, and magnetic exchange energies. For instance, charge stripes in layered nickelates typically stagger themselves from layer to layer to reduce the collective electrostatic energy arising from the charge disproportionation (9, 18).Indeed, the case of nickelates plays a prominent role in charge stripe physics (6-9, 16-19, 23-28), because mixed valent Ni 2+ (d 8 ) and Ni 3+ (d 7 ) compounds, such as La 2 − x Sr x NiO 4 (LSNO), are structurally and electronically related to high T c superconductors and thus, have been targeted as potential alternatives to the cuprates. Instead of superconductivity, however, the ground state of such quasi-2D, octahedrally coordinated nickelates is marked by stati...

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confidence: 99%

Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈

Zhang

Chen

Phelan

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

100

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“…In the same graph we also plotted the resistivity derivative curves. At T < T C2 , Σ (2) rises sharply and it is maximum at T = T C2 . Again, Σ (2) drops sharply just above T C2 .…”

Section: E Non-gaussian Nature Of Resistance Fluctuationmentioning

confidence: 98%

“…In Fig.9 the temperature evolution of the integrated second spectra Σ (2) are shown for both heating and cooling cycles. Σ (2) = fH −fL 0 s 2 (f 2 )df 2 , which is the second spectrum s 2 (f 2 ) integrated within the experimental bandwidth.…”

Section: E Non-gaussian Nature Of Resistance Fluctuationmentioning

confidence: 99%

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Dynamic phase coexistence and non-Gaussian resistance fluctuations inVO2near the metal-insulator transition

et al. 2015

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“…Moreover, the pressure can affect the electronic structure in such a way as to induce isostructural phase transitions. Insulator-to-metal transitions (IMTs) [1] and the topological changes of the Fermi surface for valence electrons, the so-called electronic topological transition (ETT) [2], represent two classic examples of electronic transitions. Investigating Os compressed to over 770 GPa, Dubrovinsky et al [3] have discovered another type of electronic transition, the core-level crossing (CLC) transition at 440 GPa, associated with interactions between the core electrons induced by pressure.…”

Section: Introductionmentioning

confidence: 99%

Pressure-induced crossing of the core levels in5dmetals

et al. 2016

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A pressure-induced interaction between core electrons, the core-level crossing (CLC) transition, has been observed in hcp Os at P ≈ 400 GPa [L. Dubrovinsky et al., Nature (London) 525, 226 (2015)]. By carrying out a systematic theoretical study for all metals of the 5d series (Hf, Ta, W, Re, Os, Ir, Pt, Au) we have found that the CLC transition is a general effect for this series of metals. While in Pt it occurs at ≈1500 GPa, at a pressure substantially higher than in Os, in Ir it occurs already at 80 GPa. Moreover, we predict that in Re the CLC transition may take place already at ambient pressure. We explain the effect of the CLC and analyze the shift of the transition pressure across the series within the Thomas-Fermi model. In particular, we show that the effect has many common features with the atomic collapse in rare-earth elements.

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Metallic and Nonmetallic Behavior in Transition Metal Oxides

Cited by 112 publications

References 28 publications

Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈

Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈

Dynamic phase coexistence and non-Gaussian resistance fluctuations inVO2near the metal-insulator transition

Pressure-induced crossing of the core levels in5dmetals

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Metallic and Nonmetallic Behavior in Transition Metal Oxides

Cited by 112 publications

References 28 publications

Stacked charge stripes in the quasi-2D trilayer nickelate La 4 Ni 3 O 8

Stacked charge stripes in the quasi-2D trilayer nickelate La 4 Ni 3 O 8

Dynamic phase coexistence and non-Gaussian resistance fluctuations inVO2near the metal-insulator transition

Pressure-induced crossing of the core levels in5dmetals

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Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈

Stacked charge stripes in the quasi-2D trilayer nickelate La ₄ Ni ₃ O ₈