Pith. sign in

REVIEW 2 major objections 6 minor 60 references

Sr$_2$NbO$_4$: A $4d$ analogue of the layered perovskite Sr$_2$VO$_4$

T0 review · 2 major / 6 minor · reviewed 2026-08-07 · deepseek-v4-flash

Pith's one-line read Sr2NbO4 is a stable, exfoliable 4d layered magnet

desk verdict A useful first computational pass at Sr2NbO4 that will likely be cited, but the headline magnetic exchange numbers rest on a nearest-neighbor Heisenberg fit that the authors themselves concede is incomplete. read the letter →

arxiv 2505.21995 v2 pith:DJSW7QWP submitted 2025-05-28 cond-mat.str-el

classification cond-mat.str-el
keywords layeredperovskiteSr2NbO4itinerantmagnetismFermisurfacenestingDFT+DMFTexfoliable2Dmaterialt2gelectronsystemRuddlesden-Popperphase
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

Sr2NbO4, a layered oxide related to the long-puzzling Sr2VO4, is argued to be a stable, potentially exfoliable compound whose niobium square planes each hold a single $t_{2g}$ electron. Using density functional theory and dynamical mean-field theory, the authors find that this electron keeps an itinerant character: the mass is only moderately renormalized ($m^*/m \sim 1.3$), and the dominant magnetic interaction is ferromagnetic within each plane ($J_{ab} = -440$ K) with a much weaker antiferromagnetic coupling between planes ($J_c = 26$ K). They also detect an imperfect Fermi-surface nesting at $Q = (\pi, \pi, 0)$, which they propose could develop into a symmetry-lowering charge or orbital density wave, or even superconductivity. If correct, the paper establishes Sr2NbO4 as a correlated 4d square-lattice itinerant magnet rather than a localized hidden-order insulator, and it gives concrete numbers for experiments to check.

What carries the argument

The central quantitative machinery is a nearest-neighbor Heisenberg model $H = \sum_{i\neq j} J \vec S_i \cdot \vec S_j$ with two exchange constants, $J_{ab}$ (in-plane) and $J_c$ (interlayer), whose values are extracted from the total energies of four collinear spin configurations (NM, FM, AFM-I, AFM-Néel, AFM-Stripe) computed with DFT+U. The second load-bearing object is the Fermi surface from nonmagnetic DFT: the cylindrical $xy$ sheet with nesting vector $Q = (\pi, \pi, 0)$. The third is the DFT+DMFT spectral calculation, which supplies the mass renormalization and the local spin correlator whose decay time yields the spin lifetime.

What would settle it

If neutron or resonant x-ray scattering on Sr2NbO4 single crystals detected in-plane antiferromagnetic order rather than ferromagnetic planes, the FM-in-plane/AFM-interlayer picture would be contradicted. Alternatively, an angle-resolved photoemission measurement showing a strongly enhanced mass ($m^*/m > 2$) or a true gap at the Fermi level would falsify the moderate-renormalization, itinerant-metallic claim.

Watch

Extended reading notes

Core claim

The central claim is that Sr2NbO4 is thermodynamically stable in the tetragonal I4/mmm Ruddlesden-Popper structure, with a negative enthalpy of formation that persists across DFT, DFT+U, and van der Waals corrected calculations, and with a (001) cleavage energy of 1.44 J/$m^{2}$, placing it in the exfoliable range. In the nonmagnetic band structure the $t_{2g}$ bands cross the Fermi level, the $xy$ band being the widest and producing a cylindrical Fermi-surface sheet with imperfect nesting at $Q = (\pi, \pi, 0)$. The DFT+DMFT calculation at 100 K yields only modest renormalization — $m^*/m = 1.32$ for $xz/yz$ and 1.18 for $xy$ — and a spin-lifetime near 35 fs, which the authors read as evidence of itinerant magnetism with strong longitudinal spin fluctuations. Fitting four collinear spin configurations to a two-parameter Heisenberg model gives ferromagnetic in-plane exchange $J_{ab} = -440$ K and antiferromagnetic interlayer exchange $J_c = 26$ K, making the static mean-field ground state AFM-I (ferromagnetic layers stacked antiferromagnetically). The paper therefore concludes that Sr2NbO4 is a correlated itinerant 4d square-lattice magnet, with nesting-driven instabilities as the route to density-wave or superconducting orders.

Load-bearing premise

The load-bearing premise is that a two-parameter nearest-neighbor Heisenberg model, fitted to the total energies of four collinear spin configurations, captures the magnetic interactions of Sr2NbO4; the paper itself notes that further-neighbor exchange can be important.

Editorial extensions

If this is right

  • Sr2NbO4 should be mechanically exfoliable into monolayer or few-layer sheets, providing a single-$t_{2g}$ square lattice for 2D magnetism and transport studies.
  • Because the in-plane exchange is strongly ferromagnetic and the interlayer exchange is weakly antiferromagnetic, bulk Sr2NbO4 should order with ferromagnetic Nb layers stacked antiferromagnetically, with the ordering temperature suppressed by two-dimensionality.
  • The imperfect nesting at $Q = (\pi, \pi, 0)$ is a genuine instability, so pressure, doping, or strain could push the system into a charge or orbital density wave or a superconducting state.
  • The small mass renormalization and short spin lifetime comparable to ZrZn2 imply that magnetic excitations are broad and damped, making Sr2NbO4 a testbed for itinerant-electron magnetism in 4d oxides.
  • The nearly zero low-temperature susceptibility seen in one earlier experiment could be naturally explained if a superconducting or diamagnetic phase develops, consistent with the nesting instability.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The pseudogap and van Hove singularity lying within about 100 meV of the Fermi level suggest Sr2NbO4 is finely balanced: the same strain or doping that sharpens the nesting could drive a density-wave transition, a scenario that resistivity and susceptibility measurements under uniaxial pressure could test.
  • If the ferromagnetic-plane picture survives treatments that include further-neighbor exchange, Sr2NbO4 would join a small group of 4d square-lattice ferromagnets where magnetic order is stabilized by orbitally dependent hopping rather than by localized spins.
  • The collinear-only fit cannot exclude noncollinear or canted states; the combination of strong in-plane ferromagnetism with weak antiferromagnetic interlayer coupling is exactly the setting where a helimagnetic or canted order could appear.
  • A direct test of the nesting prediction would be angle-resolved photoemission or optical conductivity on single crystals: a charge-density-wave transition should open a gap or pseudogap at the nested portions of the Fermi surface, and the predicted moderate effective mass could be checked against the measured bandwidth.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 6 minor

Summary. The manuscript uses DFT, DFT+U, DFT-D3, and DFT+DMFT to predict that Sr2NbO4 is a thermodynamically stable, potentially exfoliable I4/mmm layered perovskite with one t2g electron per Nb, an imperfectly nested Fermi surface at Q=(π,π,0), moderate mass renormalization (m*/m ~ 1.3), and a magnetic ground state described by ferromagnetic in-plane exchange J_ab = −440 K with much weaker antiferromagnetic interlayer exchange J_c = 26 K. The authors place the compound on a three-band Hubbard-model phase diagram proposed for Sr2VO4 and argue that Sr2NbO4 is an itinerant 4d square-lattice magnet rather than a localized hidden-order insulator.

Significance. If the predictions are correct, the paper provides a concrete new candidate for a correlated 4d square-lattice layered perovskite, with testable consequences for synthesis, exfoliation, transport, magnetic susceptibility, and possibly nesting-driven instabilities. The study is mostly ab initio: U_Nb is obtained from linear response, hopping integrals from Wannier fits, the full hopping set is retained in the DMFT impurity Hamiltonian, and stability is checked with DFT, DFT+U, and DFT-D3. The authors are also transparent about several limitations, including the possibility of further-neighbor exchange and the uncertainty in U for the t2g subshell. The main weakness is that the headline exchange constants are not yet extracted in a controlled way, which leaves the magnetic picture as the least robust part of an otherwise plausible computational proposal.

major comments (2)
  1. [Section VI A, Eq. (2), Table II] The central magnetic picture — FM in-plane J_ab = −440 K and weak AFM interlayer J_c = 26 K — is obtained by a nearest-neighbor-only Heisenberg fit to total energies at a single U = 2 eV and J_H = 0.5 eV, but neither the mapping formulas nor the fit residuals are shown, even though Table II contains five energies for only two exchange parameters. The manuscript itself concedes that further-neighbor exchange can be important, and Table S4 makes the concern concrete: t'_xy,xy = 96 meV and several third/fourth-neighbor hopping terms of 34–38 meV are only factors of 4–10 smaller than the leading nearest-neighbor hoppings, while the fitted J_ab and J_c are about 38 meV and 2.2 meV. Omitted exchange paths can therefore be comparable to or larger than the fitted interlayer coupling and may even affect the sign of J_ab. The authors should include further-neighbor exchanges in the mapping, vary U and J_H over the plausible range acknowledged in the text, and report the mapping and residuals. Without this, the FM-layer/AFM-interlayer conclusion is not controlled.
  2. [Section VI A, Table II] The use of a spin Hamiltonian with formal S = 1/2 to interpret the DFT+U total-energy differences is not justified for a metallic system with ordered moments of only ~0.5 μB. The reduced moments make the normalization of the exchange constants ambiguous, and the metallic character shown in Fig. 6 means the energy differences may not correspond to the localized Heisenberg model of Eq. (2). The authors should either justify the S = 1/2 mapping for an itinerant reduced-moment system, for example by comparing with a magnetic-force-theorem or constrained-moment calculation, or present J_ab and J_c explicitly as effective energy differences rather than literal spin-exchange couplings.
minor comments (6)
  1. [References] Reference [3] contains the typo 'Sr2Ruo4'; it should read Sr2RuO4.
  2. [Section VI A] The text says 'calculate 4 spin configurations', but Table II lists five energies including NM; please clarify which configurations enter the exchange mapping and whether the NM energy is used in the fit.
  3. [Methods (DFT+DMFT)] The double-counting correction used in the DFT+DMFT calculations is not specified; please state it explicitly so that the calculation can be reproduced.
  4. [Section VI B] The values m*/m = 1.32 and 1.18 are quoted without stating the extraction procedure, such as quasiparticle residue Z or renormalized band velocity; please specify how these numbers were obtained.
  5. [Fig. 5] The caption refers to '(a-c) three antiferromagnetic configurations', but panel (a) is the supercell drawing and only panels (b) and (c) show magnetic configurations; please align the caption with the panel labels.
  6. [Section III] The cleavage energy of 1.44 J/m² is estimated from -ICOHP bond energies rather than from explicit slab calculations; this should be stated clearly as an estimate and compared with the exfoliation threshold of Ref. [46].

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: all central results are ab initio predictions with parameters fixed by independent linear-response/cRPA/Wannier inputs, and the only overlapping-author citation is used as a non-load-bearing phase-diagram comparison.

full rationale

The central derived quantities — enthalpy of formation, cleavage energy, Fermi-surface nesting, DMFT spectral functions with m*/m ≈ 1.18–1.32, and the exchange constants — are outputs of DFT, DFT+U, and DFT+DMFT calculations whose inputs are set independently: U_Nb = 2 eV from the Cococcioni–de Gironcoli linear-response method, J_H = 0.5 eV from the published cRPA study [34], and the hopping integrals from Wannier fits to the GGA band structure. No experimental susceptibility, resistivity, or spectra are fitted, and no fitted parameter is renamed as a prediction. The Heisenberg J values in Section VI A are obtained by mapping four collinear DFT+U total energies onto Eq. (2); this is a conventional energy-mapping parametrization rather than a prediction of an independent observable, and the paper explicitly concedes that further-neighbor exchanges could matter — a completeness caveat, not a circular step. The only overlapping-author citation, Ref. [12], is used to place the computed parameters on a published three-band Hubbard phase diagram and to interpret possible orbital/entangled states; the paper even warns that the Hartree-Fock approximation of Ref. [12] is questionable for the metallic Sr2NbO4, so that self-citation is not load-bearing for the main claims. The derivation chain is self-contained against external first-principles benchmarks and does not reduce to its own inputs.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The paper introduces no new quasi-particles, forces, or dimensions. Its quantitative results rest on two interaction parameters (U, J_H), a truncated Heisenberg fit, and several method-level approximations that are standard for this field but not externally benchmarked for Sr2NbO4.

free parameters (3)
  • Hubbard U on Nb 4d orbitals (U_Nb) = 2 eV (linear response estimate; literature 1-3 eV; Ref [58] used 6 eV)
    Used in both DFT+U and DFT+DMFT. The DMFT mass renormalization and the DFT+U exchange energies depend directly on this value; the paper acknowledges it could be slightly larger for t2g.
  • Hund's exchange J_H for Nb 4d = 0.5 eV (chosen from Ref [34]; also tested 0.35 eV in DFT+U)
    Controls the relative stability of magnetic configurations and the position on the Ref [12] phase diagram; the paper varies it modestly in DFT+U but keeps 0.5 eV in DMFT.
  • Effective nearest-neighbor Heisenberg exchanges J_ab and J_c = J_ab = -440 K, J_c = 26 K
    Obtained by mapping total energies of four collinear states onto a two-parameter Heisenberg model; further-neighbor terms are neglected despite being potentially important.
assumptions (4)
  • domain assumption GGA (PBE) density functional theory provides a reliable low-energy electronic structure for Sr2NbO4.
    All band structure, Fermi surface, Wannier hoppings, and energetics derive from this approximation; there is no experimental electronic structure benchmark in the paper.
  • domain assumption The local t2g impurity in DMFT can be described with the generalized Kanamori interaction in cubic form, and spin-orbit coupling can be neglected.
    The paper states the real impurity symmetry is tetragonal and SOC was omitted from DFT+DMFT; for a 4d shell with lambda/t ~ 0.26 this is a nontrivial approximation. DFT+U+SOC is only used as a check in a different method.
  • domain assumption The four collinear spin configurations are sufficient to determine the magnetic ground state and the nearest-neighbor Heisenberg exchanges.
    No noncollinear states, spirals, or further-neighbor exchanges are computed; the paper explicitly notes further-neighbor couplings can be important.
  • domain assumption The formation reaction NbO2 + 2SrO -> Sr2NbO4 is the relevant thermodynamic decomposition channel at 0 K.
    Only this one reaction is used to assert stability; no competing products or finite-temperature contributions are considered.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Sr$_2$NbO$_4$: A $4d$ analogue of the layered perovskite Sr$_2$VO$_4$." pith.science (2026). https://pith.science/paper/DJSW7QWP

@misc{pith2026250521995,
  author       = {Pith},
  title        = {Pith review of: Sr$_2$NbO$_4$: A $4d$ analogue of the layered perovskite Sr$_2$VO$_4$},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DJSW7QWP}},
  note         = {Machine review of arXiv:2505.21995}
}
abstract

This work focuses on the layered perovskite Sr$_2$NbO$_4$, a 4$d$ analogue of Sr$_2$VO$_4$, which remains an unsolved puzzle with a possible intriguing hidden magnetic order. Using density functional theory (DFT) calculations, we demonstrate the robust thermodynamic stability and exfoliability of Sr$_2$NbO$_4$, suggesting potential applications as a 2D material. Imperfect Fermi surface nesting indicates instabilities that may drive symmetry lowering, charge/orbital density waves, or superconductivity. Dynamical mean-field theory (DMFT) calculations reveal moderate mass renormalization $(m^*/m\sim1.3)$ and an itinerant character of magnetism with strong longitudinal spin fluctuations. The exchange interaction is dominated by in-plane ferromagnetic coupling with much weaker interlayer antiferromagnetic exchange.

Figures

Figures reproduced from arXiv: 2505.21995 by the authors.

Figure 2
Figure 2. FIG. 2. Relative enthalpy of Sr [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 1
Figure 1. FIG. 1. Polyhedral representation of the Sr [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Partial DOS (solid black) obtained by DFT and spec [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
Figures from the paper (3 more)
Figure 5
Figure 5. Figure 5: FIG. 5. (a) 2 [PITH_FULL_IMAGE:figures/full_fig_p004_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. Decomposed [PITH_FULL_IMAGE:figures/full_fig_p005_6.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Imaginary time, [PITH_FULL_IMAGE:figures/full_fig_p006_8.png]

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

60 extracted references · 54 canonical work pages

  1. [58]

    Vaugier, H

    L. Vaugier, H. Jiang, and S. Biermann, Hubbard u and hund exchange j in transition metal oxides: Screening versus localization trends from constrained random phase approximation, Phys. Rev. B 86, 165105 (2012)

  2. [1]

    Maeno, H

    Y. Maeno, H. Hashimoto, K. Yoshida, S. Nishizaki, T. Fujita, J. Bednorz, and F. Lichtenberg, Supercon- ductivity in a layered perovskite without copper, Nature 372, 532 (1994)

  3. [2]

    In- terestingly, both account of the van der Waals interaction or strong Hubbard repulsion via DFT-D3 and DFT+U, respectively, do not change the situation considerably

    The results indicate that the enthalpy of formation, ∆H, is negative in DFT calculations over a wide range of pressures, including at 0 GPa (ambient pressure), con- firming that Sr 2NbO4 is thermodynamically stable. In- terestingly, both account of the van der Waals interaction or strong Hubbard repulsion via DFT-D3 and DFT+U, respectively, do not change t...

  4. [3]

    A. P. Mackenzie and Y. Maeno, The superconductivity of Sr2Ruo4 and the physics of spin-triplet pairing, Reviews of Modern Physics 75, 657 (2003)

  5. [4]

    Rice and M

    T. Rice and M. Sigrist, Sr 2RuO4: an electronic analogue of 3He?, Journal of Physics: Condensed Matter 7, L643 (1995)

  6. [5]

    Anisimov, I

    V. Anisimov, I. Nekrasov, D. Kondakov, T. Rice, and M. Sigrist, Orbital-selective mott-insulator transition in Ca 2−xSrxRuO4, The European Physical Journal B- Condensed Matter and Complex Systems 25, 191 (2002)

  7. [6]

    M. E. Barber, F. Lechermann, S. V. Streltsov, S. L. Sko- rnyakov, S. Ghosh, B. Ramshaw, N. Kikugawa, D. A. Sokolov, A. P. Mackenzie, C. W. Hicks, et al., Role of cor- relations in determining the van hove strain in Sr 2RuO4, Physical Review B 100, 245139 (2019)

  8. [7]

    de’Medici, Hund’s coupling and its key role in tuning multiorbital correlations, Physical Review B—Condensed Matter and Materials Physics 83, 205112 (2011)

    L. de’Medici, Hund’s coupling and its key role in tuning multiorbital correlations, Physical Review B—Condensed Matter and Materials Physics 83, 205112 (2011)

Show all 60 references
  1. [8]

    8 allows to calculate lifetime (∆ τ ∆ε ≥ h) of spin, which in our case turns out to be 35 fs

    Half-width (∆ ε) of its Fourier transform to real fre- quencies presented in inset of Fig. 8 allows to calculate lifetime (∆ τ ∆ε ≥ h) of spin, which in our case turns out to be 35 fs. This is somewhat longer than what was calculated for a textbook example of itinerant magnet ...

  2. [9]

    de’Medici, S

    L. de’Medici, S. R. Hassan, M. Capone, and X. Dai, Orbital-selective mott transition out of band degeneracy lifting, Physical review letters 102, 126401 (2009)

  3. [10]

    Cyrot, B

    M. Cyrot, B. Lambert-Andron, J. Soubeyroux, M. Rey, P. Dehauht, F. Cyrot-Lackmann, G. Fourcaudot, J. Beille, and J. Tholence, Properties of a new perovskite oxyde Sr 2VO4, Journal of Solid State Chemistry 85, 321 (1990)

  4. [11]

    Sugiyama, H

    J. Sugiyama, H. Nozaki, I. Umegaki, W. Higemoto, E. J. Ansaldo, J. H. Brewer, H. Sakurai, T.-h. Kao, H.-d. Yang, and M. Martin, Hidden magnetic order in Sr 2VO4 clari- fied with µ+sr, Phys. Rev. B 89, 020402 (2014)

  5. [12]

    Jackeli and G

    G. Jackeli and G. Khaliullin, Magnetically hidden order of kramers doublets in D1 systems: Sr 2VO4, Phys. Rev. Lett. 103, 067205 (2009)

  6. [13]

    B. Kim, S. Khmelevskyi, P. Mohn, and C. Franchini, Competing magnetic interactions in a spin-1/2 square lattice: Hidden order in Sr 2VO4, Physical Review B 96, 1 (2017)

  7. [14]

    P. A. Igoshev, D. E. Chizhov, V. Y. Irkhin, and S. V. Streltsov, Spin-orbit coupling induced orbital entangle- ment in a three-band hubbard model, Physical Review B 110, 115110 (2024)

  8. [15]

    G. Chen, R. Pereira, and L. Balents, Exotic phases in- duced by strong spin-orbit coupling in ordered double perovskites, Physical Review B—Condensed Matter and Materials Physics 82, 174440 (2010)

  9. [16]

    D. D. Maharaj, G. Sala, M. B. Stone, E. Kermarrec, C. Ritter, F. Fauth, C. A. Marjerrison, J. E. Greedan, A. Paramekanti, and B. D. Gaulin, Octupolar versus n´ eel order in cubic 5d2 double perovskites, Physical Review Letters 124, 87206 (2020)

  10. [17]

    L. V. Pourovskii, D. F. Mosca, and C. Franchini, Ferro- octupolar order and low-energy excitations in d2 dou- ble perovskites of osmium, Physical Review Letters 127, 237201 (2021), arXiv:2107.04493v1

  11. [18]

    Takayama, J

    T. Takayama, J. Chaloupka, A. Smerald, G. Khal- iullin, and H. Takagi, Spin-orbit-entangled electronic phases in 4d and 5d transition-metal compounds, Jour- nal of the Physical Society of Japan 90, 062001 (2021), arXiv:2102.02740

  12. [19]

    Anisimov, D

    V. Anisimov, D. Bukhvalov, and T. Rice, Electronic structure of possible nickelate analogs to the cuprates, Physical Review B 59, 7901 (1999)

  13. [20]

    D. Li, K. Lee, B. Y. Wang, M. Osada, S. Crossley, H. R. Lee, Y. Cui, Y. Hikita, and H. Y. Hwang, Supercon- ductivity in an infinite-layer nickelate, Nature 572, 624 (2019)

  14. [21]

    Hepting, D

    M. Hepting, D. Li, C. Jia, H. Lu, E. Paris, Y. Tseng, X. Feng, M. Osada, E. Been, Y. Hikita, et al. , Electronic structure of the parent compound of superconducting infinite-layer nickelates, Nature materials 19, 381 (2020)

  15. [22]

    Mitchell, Sr 2IrO4: Gateway to cuprate superconduc- tivity?, APL Materials 3 (2015)

    J. Mitchell, Sr 2IrO4: Gateway to cuprate superconduc- tivity?, APL Materials 3 (2015)

  16. [23]

    Arita, A

    R. Arita, A. Yamasaki, K. Held, J. Matsuno, and K. Kuroki, Sr 2VO4 and Ba 2VO4 under pressure: An or- bital switch and potential d 1 superconductor, Physical Review B 75, 174521 (2007)

  17. [24]

    Kasimov, E

    G. Kasimov, E. Vovkotrub, and E. Krylov, Synthesis of strontium orthoniobate, J. Inorg. Chem. 19, 148 (1974)

  18. [25]

    pauling file multinaries edition – 2022

    Sr 2TiO4 crystal structure: Datasheet from “pauling file multinaries edition – 2022” in springermaterials, copy- right 2023 Springer-Verlag Berlin Heidelberg & Material Phases Data System (MPDS), Switzerland & National Institute for Materials Science (NIMS), Japan

  19. [26]

    Isawa and M

    K. Isawa and M. Nagano, Synthesis and physical properties of niobium-based oxide, Sr2−xLaxNbO4(0 ≤ x < 0.2), Physica C: Supercon- ductivity 357-360, 359 (2001)

  20. [27]

    Nakamura, A 2Nb1+X Oy(A=Ca,Sr), Japanese Journal of Applied Physics 33, L583 (1994)

    A. Nakamura, A 2Nb1+X Oy(A=Ca,Sr), Japanese Journal of Applied Physics 33, L583 (1994)

  21. [28]

    T. Ueno, J. Kim, M. Takata, and T. Katsufuji, Ef- fect of offstoichiometry on the physical properties of sr2vo4, Journal of the Physical Society of Japan 83, 10.7566/JPSJ.83.034708 (2014)

  22. [29]

    J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 78, 1396 (1997)

  23. [30]

    Kresse and J

    G. Kresse and J. Furthm¨ uller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169 (1996)

  24. [31]

    H. J. Monkhorst and J. D. Pack, Special points for brillouin-zone integrations, Phys. Rev. B 13, 5188 (1976)

  25. [32]

    Press, B

    W. Press, B. Flannery, S. Teukolsky, and W. Vetterling, Numerical recipes : the art of scientific computing (Cam- bridge, New York, Cambridge University Press, 1986)

  26. [33]

    Momma and F

    K. Momma and F. Izumi, VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data, J. Appl. Crystallography 44, 1272 (2011)

  27. [34]

    A. I. Liechtenstein, V. I. Anisimov, and J. Zaanen, Density-functional theory and strong interactions: Or- bital ordering in mott-hubbard insulators, Phys. Rev. B 52, R5467 (1995). 8

  28. [35]

    Cococcioni and S

    M. Cococcioni and S. de Gironcoli, Linear response ap- proach to the calculation of the effective interaction pa- rameters in the LDA + U method, Phys. Rev. B 71, 035105 (2005)

  29. [36]

    S ¸a¸ sıo˘ glu, C

    E. S ¸a¸ sıo˘ glu, C. Friedrich, and S. Bl¨ ugel, Effective coulomb interaction in transition metals from con- strained random-phase approximation, Phys. Rev. B 83, 121101 (2011)

  30. [37]

    Poteryaev, A

    A. Poteryaev, A. Belozerov, A. Dyachenko, D. Korotin, M. Korotin, A. Shorikov, N. Skorikov, S. Skornyakov, and S. Streltsov, Amulet

  31. [38]

    E. Gull, A. J. Millis, A. I. Lichtenstein, A. N. Rubtsov, M. Troyer, and P. Werner, Continuous-time monte carlo methods for quantum impurity models, Reviews of Mod- ern Physics 83, 349 (2011)

  32. [39]

    Marzari and D

    N. Marzari and D. Vanderbilt, Maximally localized gen- eralized wannier functions for composite energy bands, Phys. Rev. B 56, 12847 (1997)

  33. [40]

    Marzari, A

    N. Marzari, A. A. Mostofi, J. R. Yates, I. Souza, and D. Vanderbilt, Maximally localized wannier functions: Theory and applications, Rev. Mod. Phys. 84, 1419 (2012)

  34. [41]

    A. A. Mostofi, J. R. Yates, G. Pizzi, Y. S. Lee, I. Souza, D. Vanderbilt, and N. Marzari, An updated version of Wannier90: A tool for obtaining maximally-localised wannier functions, Computer Physics Communications 185, 2309 (2014)

  35. [42]

    Georges, L

    A. Georges, L. D. Medici, and J. Mravlje, Strong correla- tions from hund’s coupling, Annual Review of Condensed Matter Physics 4, 137 (2013)

  36. [43]

    See Supplemental material at [URL will be inserted by publisher] for details of crystal structure, energy-volume curves, total and projected DOSes

  37. [44]

    S. N. Ruddlesden and P. Popper, New compounds of the K2NiF4 type, Acta Crystallographica 10, 538 (1957)

  38. [45]

    S. N. Ruddlesden and P. Popper, The compound Sr3Ti2O7 and its structure, Acta Crystallographica 11, 54 (1958)

  39. [46]

    Wells, Structural Inorganic Chemistry, 4th Edition (Oxford University Press, 1975) p

    A. Wells, Structural Inorganic Chemistry, 4th Edition (Oxford University Press, 1975) p. 498

  40. [47]

    Birch, Finite elastic strain of cubic crystals, Phys

    F. Birch, Finite elastic strain of cubic crystals, Phys. Re v. 71, 809 (1947)

  41. [48]

    Mounet, M

    N. Mounet, M. Gibertini, P. Schwaller, D. Campi, A. Merkys, A. Marrazzo, T. Sohier, I. Castelli, A. Cepel- lotti, G. Pizzi, and N. Marzari, Novel two-dimensional materials from high-throughput computational exfolia- tion of experimentally known compounds, Nature Nan- otechnolo...

  42. [49]

    Matsuno, Y

    J. Matsuno, Y. Okimoto, M. Kawasaki, and Y. Tokura, Variation of the electronic structure in systematically synthesized sr2mo4 ( m = ti , v, cr, mn, and co), Physical Review Letters 95, 176404 (2005)

  43. [50]

    M. V. Eremin, J. Deisenhofer, R. M. Eremina, J. Teyssier, D. Van Der Marel, and A. Loidl, Alternating spin-orbital order in tetragonal sr2vo4, Physical Review B 84, 4 (2011)

  44. [51]

    M. S. Hybertsen, E. Stechel, M. Schluter, and D. Jenni- son, Renormalization from density-functional theory to strong-coupling models for electronic states in Cu-O ma- terials, Physical Review B 41, 11068 (1990)

  45. [52]

    Abragam and B

    A. Abragam and B. Bleaney, Electron Paramagnetic Res- onance of Transition Ions (Clarendon press, Oxford, 1970)

  46. [53]

    Streltsov, Magnetic moment suppression in Ba3CoRu2O9: Hybridization effect, Physical Review B 88, 024429 (2013)

    S. Streltsov, Magnetic moment suppression in Ba3CoRu2O9: Hybridization effect, Physical Review B 88, 024429 (2013)

  47. [54]

    Katanin, A

    A. Katanin, A. Belozerov, A. Lichtenstein, and M. Kat- snelson, Exchange interactions in iron and nickel: Dft+ dmft study in paramagnetic phase, Physical Review B 107, 235118 (2023)

  48. [55]

    Igoshev, A

    P. Igoshev, A. Efremov, A. Poteryaev, A. Katanin, and V. Anisimov, Magnetic fluctuations and effective mag- netic moments in γ-iron due to electronic structure pe- culiarities, Physical Review B—Condensed Matter and Materials Physics 88, 155120 (2013)

  49. [56]

    S. V. Streltsov, D. Takegami, R. Nakamura, P. P. Koval- eva, A. I. Poteryaev, S. A. Nikolaev, H.-H. Xu, Y. Sui, M. Yoshimura, K.-D. Tsuei, N. L. Saini, D. I. Khomskii, and T. Mizokawa, Beyond a cluster-mott state in the breathing kagome lattice of lizn2mo3o8, Physical Review B...

  50. [57]

    Moriya, Spin Fluctuations in Itinerant Electron Mag- netism (Springer Berlin Heidelberg, 2012)

    T. Moriya, Spin Fluctuations in Itinerant Electron Mag- netism (Springer Berlin Heidelberg, 2012)

  51. [59]

    G. C. Moore, M. K. Horton, E. Linscott, A. M. Ganose, M. Siron, D. D. O’Regan, and K. A. Persson, High- throughput determination of hubbard u and hund j val- ues for transition metal oxides via the linear response formalism, Physical Review Materials 8, 014409 (2024)

  52. [60]

    Paul and T

    A. Paul and T. Birol, Strain tuning of plasma frequency in vanadate, niobate, and molybdate perovskite oxides, Physical Review Materials 3, 085001 (2019). Supplemental material for: Sr 2NbO4: A 4d analogue of the layered perovskite Sr 2VO4 Leonid S. Taran, 1, ∗ Anastasia E. Le...

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.