pith. sign in

arxiv: 2606.27040 · v1 · pith:OXW3NTCFnew · submitted 2026-06-25 · ❄️ cond-mat.supr-con · cond-mat.str-el

High temperature transitions in Ruddlesden-Popper nickelates La_(n+1)Ni_(n)O_(3n+1)

P. Reiss , A. Shevchenko , P. S. Lizama , J. Nuss , R. Dinnebier , P. A. van Aken , M. Hepting , M. Isobe
show 4 more authors
Y. E. Suyolcu H. Takagi B. Keimer P. Puphal
This is my paper

Pith reviewed 2026-06-26 02:10 UTC · model grok-4.3

classification ❄️ cond-mat.supr-con cond-mat.str-el
keywords Ruddlesden-Popper nickelateshigh-temperature phase transitionsingle crystalLa3Ni2O7heat capacitymagnetic susceptibilitytransport measurements
0
0 comments X

The pith

High-quality single crystals reveal a distinct high-temperature phase transition in the full series of Ruddlesden-Popper nickelates La_{n+1}Ni_n O_{3n+1}.

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

The paper measures the complete series of bulk-stable La_{n+1}Ni_n O_{3n+1} compounds with single-crystal and powder X-ray diffraction, electron microscopy, heat capacity, differential scanning calorimetry, magnetic susceptibility, and transport from 2 K to 1000 K. It reports anomalies that mark a high-temperature phase transition different from the known transition into the tetragonal phase. A sympathetic reader would care because these materials are the parent compounds for the recently discovered nickelate superconductors, and unresolved discrepancies between published reports may trace to this overlooked transition.

Core claim

By studying high-quality single crystals, we identify a previously underappreciated high-temperature phase transition in Ruddlesden-Popper nickelates La_{n+1}Ni_n O_{3n+1} distinct from the one going to a tetragonal phase.

What carries the argument

The high-temperature phase transition, detected as anomalies in calorimetry, susceptibility, and transport measurements on single crystals across the n series.

If this is right

  • Phase diagrams for the entire La_{n+1}Ni_n O_{3n+1} family must incorporate this additional transition above room temperature.
  • Transport and magnetic data collected up to 1000 K require reinterpretation in light of the new transition.
  • Discrepancies among earlier reports on these nickelates are at least partly attributable to the transition being missed in lower-quality samples.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The transition temperature may set an upper limit on the temperature window relevant for studying the emergence of superconductivity in doped variants.
  • Systematic mapping of how the transition temperature varies with n could reveal whether it tracks the same structural motifs that enable superconductivity at n=2.
  • If the transition involves oxygen rearrangement, it would imply that oxygen stoichiometry must be controlled even at high temperatures during crystal growth.

Load-bearing premise

The observed anomalies correspond to an intrinsic bulk phase transition rather than extrinsic effects such as oxygen loss, surface reconstruction, or minor impurity phases.

What would settle it

Absence of the high-temperature anomalies in additional single crystals prepared with stricter oxygen stoichiometry control or in measurements that isolate surface versus bulk response.

Figures

Figures reproduced from arXiv: 2606.27040 by A. Shevchenko, B. Keimer, H. Takagi, J. Nuss, M. Hepting, M. Isobe, P. A. van Aken, P. Puphal, P. Reiss, P. S. Lizama, R. Dinnebier, Y. E. Suyolcu.

Figure 2
Figure 2. Figure 2: FIG. 2. Contour plots of powder X-ray diffraction (PXRD) [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 1
Figure 1. Figure 1: FIG. 1. Crystal structures of Ruddlesden–Popper nicke [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Temperature evolution of lattice parameters extracted from Rietveld refinement of PXRD data (see supplemental [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. Differential scanning calorimetry (DSC) measure [PITH_FULL_IMAGE:figures/full_fig_p004_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6. Magnetic susceptibility of single crystals of [PITH_FULL_IMAGE:figures/full_fig_p005_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7. Electrical resistance of selected single crystals shown [PITH_FULL_IMAGE:figures/full_fig_p006_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8. Room-temperature single-crystal X-ray diffraction [PITH_FULL_IMAGE:figures/full_fig_p007_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: FIG. 9. High-magnification STEM–HAADF images of the Ruddlesden–Popper La [PITH_FULL_IMAGE:figures/full_fig_p008_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: FIG. 10. Optical floating-zone (OFZ) grown boules of nickelates labeled with the corresponding phase La [PITH_FULL_IMAGE:figures/full_fig_p013_10.png] view at source ↗
Figure 12
Figure 12. Figure 12: FIG. 12. Temperature evolution of lattice parameters and [PITH_FULL_IMAGE:figures/full_fig_p014_12.png] view at source ↗
Figure 11
Figure 11. Figure 11: FIG. 11. Powder X-ray diffraction results of (a) pow [PITH_FULL_IMAGE:figures/full_fig_p014_11.png] view at source ↗
Figure 14
Figure 14. Figure 14: FIG. 14. Contact geometries on selected single crystals of [PITH_FULL_IMAGE:figures/full_fig_p015_14.png] view at source ↗
Figure 13
Figure 13. Figure 13: FIG. 13. Temperature evolution of lattice parameters and Ni [PITH_FULL_IMAGE:figures/full_fig_p015_13.png] view at source ↗
Figure 15
Figure 15. Figure 15: FIG. 15. Low-temperature single-crystal X-ray diffraction in [PITH_FULL_IMAGE:figures/full_fig_p016_15.png] view at source ↗
Figure 16
Figure 16. Figure 16: FIG. 16. Temperature evolution of lattice parameters and Ni [PITH_FULL_IMAGE:figures/full_fig_p017_16.png] view at source ↗
Figure 17
Figure 17. Figure 17: FIG. 17. Structure at room temperature of La [PITH_FULL_IMAGE:figures/full_fig_p018_17.png] view at source ↗
read the original abstract

The discovery of superconductivity at $15\,\mathrm{K}$ in the infinite-layer nickelate $(\mathrm{Nd},\mathrm{Sr})\mathrm{NiO}_2$, followed by superconductivity at $80\,\mathrm{K}$ in the Ruddlesden--Popper phase $\mathrm{La}_3\mathrm{Ni}_2\mathrm{O}_7$, has ushered in a new era of nickelate research. Despite this progress, large discrepancies between reports exist. Here, we investigate the complete series of bulk-stable $\mathrm{La}_{n+1}\mathrm{Ni}_n\mathrm{O}_{3n+1}$ compounds using a comprehensive set of experimental techniques, including PXRD, single-crystal XRD, electron microscopy, heat capacity, differential scanning calorimetry, magnetic susceptibility, and transport measurements, over a broad temperature range from $2$ to $1000\,\mathrm{K}$. By studying high-quality single crystals, we identify a previously underappreciated high-temperature phase transition in Ruddlesden--Popper nickelates $\mathrm{La}_{n+1}\mathrm{Ni}_n\mathrm{O}_{3n+1}$ distinct from the one going to a tetragonal phase.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript investigates the full series of bulk-stable Ruddlesden-Popper nickelates La_{n+1}Ni_nO_{3n+1} using PXRD, single-crystal XRD, electron microscopy, heat capacity, DSC, magnetic susceptibility, and transport measurements from 2 to 1000 K on high-quality single crystals. It claims to identify a previously underappreciated high-temperature phase transition distinct from the transition to the tetragonal phase.

Significance. If the reported anomalies are shown to be intrinsic bulk transitions rather than extrinsic effects, the result would clarify the high-temperature phase diagram of these nickelates and inform the conditions under which superconductivity emerges in related reduced phases. The use of single crystals across the n series is a strength, but the absence of quantitative data, error analysis, or explicit controls in the provided abstract limits assessment of impact.

major comments (2)
  1. [Abstract / Results] The central claim that the observed anomalies correspond to an intrinsic bulk phase transition (distinct from the tetragonal one) rests on the weakest assumption that they survive controls for oxygen stoichiometry, surface effects, or minor impurities. No specific section, figure, or table is cited in the abstract to demonstrate such controls (e.g., post-measurement oxygen content analysis or comparison to deliberately off-stoichiometric samples).
  2. [Abstract] Without presented data, figures, or quantitative analysis (e.g., transition temperatures, latent heats, or susceptibility jumps with error bars), it is not possible to evaluate whether the anomalies are reproducible across the n series or distinguishable from known literature transitions.
minor comments (1)
  1. [Abstract] The abstract would benefit from a brief statement of the key quantitative signatures (e.g., transition temperature range or magnitude of specific-heat anomaly) to allow readers to assess novelty immediately.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful review and constructive feedback. We address the major comments point-by-point below, with revisions to improve clarity in the abstract while preserving the manuscript's focus on the experimental evidence from single-crystal studies.

read point-by-point responses

  1. Referee: [Abstract / Results] The central claim that the observed anomalies correspond to an intrinsic bulk phase transition (distinct from the tetragonal one) rests on the weakest assumption that they survive controls for oxygen stoichiometry, surface effects, or minor impurities. No specific section, figure, or table is cited in the abstract to demonstrate such controls (e.g., post-measurement oxygen content analysis or comparison to deliberately off-stoichiometric samples).

    Authors: We agree the abstract does not cite specific controls or figures, as is conventional for brevity. The full manuscript details high-quality single-crystal growth and characterization via PXRD, single-crystal XRD, electron microscopy, and multiple physical property measurements (heat capacity, DSC, susceptibility, transport) from 2-1000 K, with consistency across the n series supporting intrinsic bulk behavior. We have revised the abstract to reference the relevant methods and results sections demonstrating sample quality and reproducibility. revision: yes

  2. Referee: [Abstract] Without presented data, figures, or quantitative analysis (e.g., transition temperatures, latent heats, or susceptibility jumps with error bars), it is not possible to evaluate whether the anomalies are reproducible across the n series or distinguishable from known literature transitions.

    Authors: The abstract is intentionally concise and does not contain quantitative details or figures. The manuscript body includes quantitative transition temperatures, calorimetric data (latent heats via DSC), susceptibility jumps, and error analysis across multiple n values, with explicit distinction from the tetragonal transition based on temperature ranges and structural data. We have updated the abstract to summarize key quantitative findings and their distinction from literature transitions, with citations to the corresponding figures and tables. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental report with no derivation chain

full rationale

The manuscript is a purely experimental study reporting PXRD, single-crystal XRD, calorimetry, susceptibility, and transport data on La_{n+1}Ni_nO_{3n+1} crystals. No equations, ansatzes, fitted parameters, or theoretical derivations appear. Claims rest on direct laboratory measurements benchmarked against external standards and prior independent literature; no self-referential reduction of any result to its own inputs is present.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Purely experimental work; no free parameters, axioms, or invented entities are introduced. The central claim rests on standard interpretations of calorimetry and diffraction data as signatures of phase transitions.

pith-pipeline@v0.9.1-grok · 5803 in / 1223 out tokens · 29971 ms · 2026-06-26T02:10:29.293596+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Density waves in low-pressure bilayer nickelates

    cond-mat.str-el 2026-06 unverdicted novelty 6.0

    Unrestricted Hartree-Fock calculations show the second density-wave transition in La3Ni2O7 originates from double-stripe spin order becoming unstable toward a commensurate charge-density wave, yielding intertwined spi...

Reference graph

Works this paper leans on

46 extracted references · 1 canonical work pages · cited by 1 Pith paper

  1. [1]

    The X-ray source was a 9 kW ro- tating anode tube with Cu K α1,2 (G¨ obel mirror filtered, λ= 1.54 ˚A) radiation

    Rigaku SmartLab SE operating in a parallel beam reflection geometry with HyPix-3000 semiconductor de- tector in 1D mode. The X-ray source was a 9 kW ro- tating anode tube with Cu K α1,2 (G¨ obel mirror filtered, λ= 1.54 ˚A) radiation. The sample was packed into a single-crystal Si 911 sampleholder with 0.4 mm cavity. Before the measurement the sample was ...

  2. [2]

    Greenblatt, Ruddlesden-popper Ln n+1NinO3n+1 nickelates: structure and properties, Curr

    M. Greenblatt, Ruddlesden-popper Ln n+1NinO3n+1 nickelates: structure and properties, Curr. Opin. Solid State Mater. Sci.2, 174 (1997)

    1997

  3. [3]

    J. G. Bednorz and K. A. M¨ uller, Perovskite-Type Ox- ides—the New Approach to High-T C Superconductivity. Nobel Lecture, Angewandte Chemie International Edi- tion in English27, 735 (1988)

    1988

  4. [4]

    Acrivos, M

    J. Acrivos, M. Lei, C. Jiang, H. Nguyen, P. Metcalf, and J. Honig, Paramagnetism, antiferromagnetism, and su- perconductivity in La 2NiO4, J. Solid State Chem.111, 343 (1994)

    1994

  5. [5]

    Sachan, D

    V. Sachan, D. J. Buttrey, J. M. Tranquada, J. E. Lorenzo, and G. Shirane, Charge and spin ordering in La2−xSrxNiO4.00 with x=0.135 and 0.20, Phys. Rev. B 51, 12742 (1995)

    1995

  6. [6]

    Sugai, M

    S. Sugai, M. Sato, T. Kobayashi, J. Akimitsu, T. Ito, H. Takagi, S. Uchida, S. Hosoya, T. Kajitani, and T. Fukuda, High-energy spin excitations in the insu- lating phases of high-T c superconducting cuprates and La2NiO4, Phys. Rev. B42, 1045 (1990)

    1990

  7. [7]

    H. Sun, M. Huo, X. Hu, J. Li, Z. Liu, Y. Han, L. Tang, Z. Mao, P. Yang, B. Wang, J. Cheng, D.-X. Yao, G.-M. Zhang, and M. Wang, Signatures of superconductivity near 80 K in a nickelate under high pressure, Nature621, 493 (2023)

    2023

  8. [8]

    Z. Luo, X. Hu, M. Wang, W. W´ u, and D.-X. Yao, Bilayer Two-Orbital Model of La 3Ni2O7 under Pressure, Phys. Rev. Lett.131, 126001 (2023)

    2023

  9. [9]

    Zhang, L.-F

    Y. Zhang, L.-F. Lin, A. Moreo, and E. Dagotto, Elec- tronic structure, dimer physics, orbital-selective behav- ior, and magnetic tendencies in the bilayer nickelate su- perconductor La 3Ni2O7 under pressure, Phys. Rev. B 108, L180510 (2023)

    2023

  10. [10]

    Wang, H.-H

    M. Wang, H.-H. Wen, T. Wu, D.-X. Yao, and T. Xiang, Normal and Superconducting Properties of La 3Ni2O7, Chinese Physics Letters41, 077402 (2024)

    2024

  11. [11]

    Sakakibara, M

    H. Sakakibara, M. Ochi, H. Nagata, Y. Ueki, H. Saku- rai, R. Matsumoto, K. Terashima, K. Hirose, H. Ohta, M. Kato, Y. Takano, and K. Kuroki, Theoretical analy- sis on the possibility of superconductivity in the trilayer Ruddlesden-Popper nickelate La 4Ni3O10 under pressure and its experimental examination: Comparison with La3Ni2O7, Phys. Rev. B109, 144511 (2024)

    2024

  12. [12]

    Y. Zhu, D. Peng, E. Zhang, B. Pan, X. Chen, L. Chen, H. Ren, F. Liu, Y. Hao, N. Li, Z. Xing, F. Lan, J. Han, J. Wang, D. Jia, H. Wo, Y. Gu, Y. Gu, L. Ji, W. Wang, H. Gou, Y. Shen, T. Ying, X. Chen, W. Yang, H. Cao, C. Zheng, Q. Zeng, J.-g. Guo, and J. Zhao, Superconduc- tivity in pressurized trilayer La4Ni3O10−δ single crystals, Nature631, 531 (2024)

    2024

  13. [13]

    X. Chen, J. Zhang, A. S. Thind, S. Sharma, H. LaBol- lita, G. Peterson, H. Zheng, D. P. Phelan, A. S. Botana, R. F. Klie, and J. F. Mitchell, Polymorphism in the Ruddlesden–Popper Nickelate La 3Ni2O7: Discovery of a Hidden Phase with Distinctive Layer Stacking, Journal of the American Chemical Society146, 3640 (2024). [13]Puphal, P., P. Reiss, N. Enderlei...

    2024

  14. [14]

    H. Wang, L. Chen, A. Rutherford, H. Zhou, and W. Xie, Long-Range Structural Order in a Hidden Phase of Ruddlesden–Popper Bilayer Nickelate La 3Ni2O7, Inor- ganic Chemistry63, 5020 (2024)

    2024

  15. [15]

    F. Li, N. Guo, Q. Zheng, Y. Shen, S. Wang, Q. Cui, C. Liu, S. Wang, X. Tao, G.-M. Zhang, and J. Zhang, Design and synthesis of three-dimensional hy- brid Ruddlesden-Popper nickelate single crystals, Physi- cal Review Materials8, 053401 (2024)

    2024

  16. [16]

    M. Shi, D. Peng, K. Fan, Z. Xing, S. Yang, Y. Wang, H. Li, R. Wu, M. Du, B. Ge, Z. Zeng, Q. Zeng, J. Ying, T. Wu, and X. Chen, Pressure induced superconductivity in hybrid Ruddlesden–Popper La5Ni3O11 single crystals, Nature Physics21, 1780 (2025)

    2025

  17. [17]

    Huang, J

    C. Huang, J. Li, X. Huang, H. Zhang, D. Hu, M. Huo, X. Chen, Z. Chen, H. Sun, and M. Wang, Superconduc- tivity in monolayer-trilayer phase of la 3ni2o7 under high pressure (2025)

    2025

  18. [18]

    E. K. Ko, Y. Yu, Y. Liu, L. Bhatt, J. Li, V. Thampy, C.-T. Kuo, B. Y. Wang, Y. Lee, K. Lee, J.-S. Lee, B. H. Goodge, D. A. Muller, and H. Y. Hwang, Signa- tures of ambient pressure superconductivity in thin film La3Ni2O7, Nature638, 935 (2024)

    2024

  19. [19]

    G. Zhou, W. Lv, H. Wang, Z. Nie, Y. Chen, Y. Li, H. Huang, W.-Q. Chen, Y.-J. Sun, Q.-K. Xue, and Z. Chen, Ambient-pressure superconductivity onset above 40 K in (La,Pr) 3Ni2O7 films, Nature640, 641 (2025)

    2025

  20. [20]

    Y. Liu, E. K. Ko, Y. Tarn, L. Bhatt, J. Li, V. Thampy, B. H. Goodge, D. A. Muller, S. Raghu, Y. Yu, and H. Y. Hwang, Superconductivity and normal-state transport in compressively strained La 2PrNi2O7 thin films, Nature Materials24, 1221–1227 (2025)

    2025

  21. [21]

    Puphal, T

    P. Puphal, T. Sch¨ afer, B. Keimer, and M. Hepting, Su- perconductivity in infinite-layer and ruddlesden–popper nickelates, Nature Reviews Physics8, 70 (2025)

    2025

  22. [22]

    S. V. Mandyam, E. Wang, Z. Wang, B. Chen, N. C. Jayarama, A. Gupta, E. A. Riesel, V. I. Levitas, C. R. Laumann, and N. Y. Yao, Uncovering origins of hetero- geneous superconductivity in La 3Ni2O7, Nature651, 54 (2026)

    2026

  23. [23]

    Z. Dong, M. Huo, J. Li, J. Li, P. Li, H. Sun, L. Gu, Y. Lu, M. Wang, Y. Wang, and Z. Chen, Visualization of oxy- gen vacancies and self-doped ligand holes in La3Ni2O7−δ, Nature630, 847 (2024)

    2024

  24. [24]

    Z. Dong, G. Wang, N. Wang, W.-H. Dong, L. Gu, Y. Xu, J. Cheng, Z. Chen, and Y. Wang, Interstitial oxy- gen order and its competition with superconductivity in La2PrNi2O7+δ, Nature Materials24, 1927 (2025)

    1927

  25. [25]

    Kobayashi, S

    Y. Kobayashi, S. Taniguchi, M. Kasai, M. Sato, T. Nish- ioka, and M. Kontani, Transport and Magnetic Proper- ties of La 3Ni2O7−δ and La4Ni3O10−δ, J. Phys. Soc. Jpn. 65, 3978 (1996)

    1996

  26. [26]

    G. AMOW, I. DAVIDSON, and S. SKINNER, A comparative study of the Ruddlesden-Popper series, Lan+1NinO3n+1 (n=1, 2 and 3), for solid-oxide fuel-cell cathode applications, Solid State Ionics177, 1205 (2006)

    2006

  27. [27]

    Zinkevich, N

    M. Zinkevich, N. Solak, H. Nitsche, M. Ahrens, and F. Aldinger, Stability and thermodynamic functions of 12 lanthanum nickelates, Journal of Alloys and Compounds 438, 92 (2007)

    2007

  28. [28]

    Sasaki, H

    H. Sasaki, H. Harashina, S. Taniguchi, M. Kasai, Y. Kobayashi, M. Sato, T. Kobayashi, T. Ikeda, M. Takata, and M. Sakata, Structural Studies on the Phase Transition of La3Ni2O6.92 at about 550 K, Journal of the Physical Society of Japan66, 1693 (1997)

    1997

  29. [29]

    Tamura, A

    H. Tamura, A. Hayashi, and Y. Ueda, Phase diagram of La2NiO4+δ (0≤δ≤0.18) II. Thermodynamics of excess oxygen, phase transitions (0.06≤δ <0.11) and phase segregation (0.03≤6<0.06), Physica C: Superconduc- tivity258, 61 (1996)

    1996

  30. [30]

    Hayashi, H

    A. Hayashi, H. Tamura, and Y. Ueda, Successive struc- tural phase transitions in stoichiometric La 2NiO4 ob- served by X-ray diffraction, Physica C: Superconductiv- ity216, 77 (1993)

    1993

  31. [31]

    Zhang, H

    J. Zhang, H. Zheng, Y.-S. Chen, Y. Ren, M. Yonemura, A. Huq, and J. F. Mitchell, High oxygen pressure floating zone growth and crystal structure of the metallic nicke- latesR 4Ni3O10 (R=La,Pr ), Physical Review Materials 4, 083402 (2020)

    2020

  32. [32]

    M. L. Medarde, Structural, magnetic and electronic prop- erties of perovskites (r = rare earth), Journal of Physics: Condensed Matter9, 1679 (1997)

    1997

  33. [33]

    G. Wu, J. J. Neumeier, and M. F. Hundley, Magnetic sus- ceptibility, heat capacity, and pressure dependence of the electrical resistivity of La 3Ni2O7 and La 4Ni3O10, Phys. Rev. B63, 245120 (2001)

    2001

  34. [34]

    Taniguchi, T

    S. Taniguchi, T. Nishikawa, Y. Yasui, Y. Kobayashi, J. Takeda, S.-i. Shamoto, and M. Sato, Transport, Mag- netic and Thermal Properties of La 3Ni2O7−δ, J. Phys. Soc. Jpn.64, 1644 (1995)

    1995

  35. [35]

    Khasanov, T

    R. Khasanov, T. J. Hicken, H. Luetkens, Z. Guguchia, D. J. Gawryluk, V. Sundaramurthy, A. Suthar, M. Isobe, B. Keimer, G. Khaliullin, M. Hepting, and P. Puphal, Magnetism of the alternating monolayer-trilayer phase of La3Ni2O7 (2025)

    2025

  36. [36]

    Z. Liu, H. Sun, M. Huo, X. Ma, Y. Ji, E. Yi, L. Li, H. Liu, J. Yu, Z. Zhang, Z. Chen, F. Liang, H. Dong, H. Guo, D. Zhong, B. Shen, S. Li, and M. Wang, Evidence for charge and spin density waves in single crystals of La3Ni2O7 and La3Ni2O6, Sci. China Phys. Mech. Astron. 66, 217411 (2022)

    2022

  37. [37]

    Misawa, S

    R. Misawa, S. Kitou, J.-P. Sun, Y. Yu, C. Koyama, Y. Nakamura, T.-h. Arima, J.-G. Cheng, and M. Hirschberger, Polar, checkerboard charge order in bilayer nickelate La 3Ni2O7 (2026)

    2026

  38. [38]

    See Supplemental Material at [URL will be inserted by publisher] for further details, which includes Refs xxx

  39. [39]

    H¨ ucker, K

    M. H¨ ucker, K. Chung, M. Chand, T. Vogt, J. M. Tran- quada, and D. J. Buttrey, Oxygen and strontium codop- ing of La 2NiO4: Room-temperature phase diagrams, Physical Review B70, 064105 (2004)

    2004

  40. [40]

    Ferenc Segedin, J

    D. Ferenc Segedin, J. Kim, H. LaBollita, N. K. Taylor, K.-Y. Baek, S. H. Sung, A. B. Turkiewicz, G. A. Pan, A. Y. Jiang, M. Bambrick-Santoyo, T. Schwaigert, C. K. Kim, A. Tenneti, A. J. Grutter, S. Muramoto, A. T. N’Diaye, I. El Baggari, D. A. Walko, C. M. Brooks, A. S. Botana, D. G. Schlom, H. Zhou, and J. A. Mundy, Topochemical oxidation of ruddlesden–p...

    2026

  41. [41]

    N. Yuan, A. Elghandour, J. Arneth, K. Dey, and R. Klin- geler, High-pressure crystal growth and investigation of the metal-to-metal transition of Ruddlesden–Popper tri- layer nickelates La 4Ni3O10, Journal of Crystal Growth 627, 127511 (2024)

    2024

  42. [42]

    M. Shi, Y. Li, Y. Wang, D. Peng, S. Yang, H. Li, K. Fan, K. Jiang, J. He, Q. Zeng, D. Song, B. Ge, Z. Xiang, Z. Wang, J. Ying, T. Wu, and X. Chen, Absence of su- perconductivity and density-wave transition in ambient- pressure tetragonal La 4Ni3O10, Nature Communications 16, 10.1038/s41467-025-57264-0 (2025)

    work page doi:10.1038/s41467-025-57264-0 2025

  43. [43]

    V. M. Goldschmidt, Die Gesetze der Krystallochemie, Die Naturwissenschaften14, 477 (1926)

    1926

  44. [44]

    Pauling, The principles determining the structure of complex ionic crystals, Journal of the American Chemical Society51, 1010 (1929)

    L. Pauling, The principles determining the structure of complex ionic crystals, Journal of the American Chemical Society51, 1010 (1929)

    1929

  45. [45]

    Herlihy, W.-T

    A. Herlihy, W.-T. Chen, C. Ritter, Y.-C. Chuang, and M. S. Senn, Interplay between jahn–teller distortions and structural phase transitions in ruddlesden–poppers, Jour- nal of the American Chemical Society147, 7209 (2025)

    2025

  46. [46]

    Zheng, B.-X

    H. Zheng, B.-X. Wang, D. Phelan, J. Zhang, Y. Ren, M. Krogstad, S. Rosenkranz, R. Osborn, and J. Mitchell, Oxygen Inhomogeneity and Reversibility in Single Crys- tal LaNiO3−δ, Crystals10, 557 (2020). IV. SUPPLEMENTAL MATERIAL A. Growth For perovskite nickelates withn=∞,RENiO 3, it is well established that the degree of octahedral buck- ling strongly depen...

    2020