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REVIEW 3 major objections 5 minor 6 references

Stacking transition in rhombohedral graphite

T0 review · 3 major / 5 minor · reviewed 2026-08-14 · deepseek-v4-flash

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Pith's one-line read ABC-stacked few-layer graphene can be switched to common ABA stacking locally and controllably by Joule heating or by laser-pulse trains, with the transition driven by thermal stress and propagating through a moving domain wall.

desk verdict Local switching of ABC to ABA is credible; the TEM quantification is not. read the letter →

arxiv 1908.06284 v1 pith:QMVPU5BP submitted 2019-08-17 cond-mat.mes-hall cond-mat.mtrl-sciphysics.ins-det

Tataiana Latychevskaia , Seok-Kyun Son , Yaping Yang , Dale Chancellor , Michael Brown , Servet Ozdemir , Ivan Madan , Gabriele Berruto
show 3 more authors
Fabrizio Carbone Artem Mishchenko Kostya Novoselov
This is my paper · ORCID
classification cond-mat.mes-hallcond-mat.mtrl-sciphysics.ins-det PACS 81.05.ue81.05.uf78.67.Bf68.37.-d61.05.J
keywords graphenegraphitevanderWaalsheterostructuresdomainwallRamanspectroscopytransmissionelectronmicroscopydiffractionstructuraltransition
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

This paper claims that the metastable ABC (rhombohedral) stacking of few-layer graphene can be converted, locally and controllably, into the common ABA (Bernal) stacking by two heating routes: passing a current through the device, or illuminating it with a rapid train of femtosecond laser pulses. In both cases the authors argue that the switch is thermal, that it starts at a small spot and spreads by shifting the boundary (domain wall) between the two stackings, and that the boundary can be watched while it moves. The claim matters because the two stackings have very different electronic properties — ABC trilayers host an electrically tunable band gap, while ABA trilayers behave as a semimetal — so a writable, local switch between them would allow stacking patterns to be engineered inside a single flake. The paper also reports that single laser pulses, even ones that transiently heat the lattice above 3000 K, do not trigger the transition, which places the switching time at nanoseconds or longer.

What carries the argument

The load-bearing mechanism is thermally driven, stress-mediated motion of a stacking domain wall. Under Joule heating the device is modeled as two resistors in series, with the ABC domain more resistive and therefore hotter; because thermal expansion is restricted, compressive stress builds at the wall and pushes it once a threshold pressure is reached — the paper estimates 6–36 GPa across the three observed transition steps, in the same range as a previously reported value of about 22 GPa. Stacking identification rests on two discriminators: the Raman 2D-peak ratio $R = I_3/I_2$ after fitting three Lorentzians ($R < 1.3$ for ABC, $R > 1.7$ for ABA), and the electron-diffraction ratio of first-order to second-order peak intensities, which is converted to an ABA fraction by the linear formula $F_{\mathrm{ABA}} \approx (R - 0.005)/0.444$ (first-order diffraction peaks are nearly extinct for ABC stacking). Dark-field imaging that selects the (1-100) Bragg peak makes the ABA domain bright and the ABC domain dark, allowing the wall to be located at about 9 nm resolution.

What would settle it

A decisive and directly observable test is to take a flake that the paper's classifiers assign a partial conversion — for instance about 30% ABA after laser illumination — and image the same area at atomic resolution with scanning tunneling microscopy or cross-sectional annular dark-field scanning transmission electron microscopy, both established for graphene. If the true areal fraction of converted stacking disagrees with the fraction that the Raman ratio thresholds and the linear diffraction formula assign, then the empirical calibrations are mislabeling partial transitions, and the claimed stepwise switching progression and moving-domain-wall picture would not be established; agreement would confirm them.

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Extended reading notes

Core claim

The paper's central claim is that ABC-stacked few-layer graphene can be switched to ABA stacking locally and controllably by Joule heating or by laser-pulse illumination, with the transition driven by compressive stress and progressing by domain-wall motion rather than by a single simultaneous shift of all layers. In the Joule-heating experiment on an hBN-encapsulated ABC flake, Raman mapping of the 2D peak — using the intensity ratio $R = I_3/I_2$ of fitted Lorentzian sub-peaks, with $R < 1.3$ indicating ABC and $R > 1.7$ indicating ABA — shows conversion starting at one end of the channel at 3.5 V and spreading until the whole device becomes ABA at 9 V. In the electron microscope, single 790 nm pulses at fluences up to about 150 mJ/cm$^2$ produced no transition, while a 120 ms train at 100 kHz repetition rate converted part of an ABC region to ABA, showing that heat accumulation over many pulses is required; a linear calibration from simulated diffraction patterns, $F_{\mathrm{ABA}} \approx (R - 0.005)/0.444$, converts the measured first-to-second-order peak ratio into an ABA fraction and yields a partial transition with about 32% ABA after illumination. Dark-field imaging selecting the (1-100) diffraction spot renders ABA bright and ABC dark, resolving the domain wall at about 9 nm. The authors conclude that both switching routes are thermal, that the wall moves as conversion proceeds, and that the transition takes nanoseconds or longer.

Load-bearing premise

The load-bearing premise is that the two measuring recipes used to tell the two stackings apart — the shape of the scattered-light peak in one experiment and the brightness ratio of electron-diffraction rings in the other — are accurate enough to identify a partly converted sample; if either recipe mislabels a partially converted region, the claimed stepwise switching and the moving boundary between the two stackings would not be established.

Editorial extensions

If this is right

  • Stacking order becomes a writable, local degree of freedom: Joule heating switches regions on the micrometer scale, while laser-pulse trains switch areas of roughly 20–40 μm.
  • The transition is thermal and accumulative: single femtosecond pulses that transiently exceed 3000 K do not switch stacking, whereas a 100 kHz train that builds up heat does, placing the transition on a nanosecond-or-longer timescale.
  • Conversion proceeds by domain-wall motion: the wall shifted progressively along the channel during Joule heating until the entire device became ABA, and was imaged directly at about 9 nm resolution in dark-field electron microscopy.
  • Diffraction ratios quantify partial conversion: the formula $F_{\mathrm{ABA}} \approx (R - 0.005)/0.444$ assigns about 32% ABA stacking after laser illumination, showing that the switch can be partial rather than all-or-nothing.
  • Dark-field imaging tracks the wall at roughly 9 nm resolution, an order of magnitude better than the about 1 μm Raman maps, opening nanoscale study of stacking solitons during a thermally driven transition.

Reading between the lines

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

  • If the stress-threshold picture is correct, interrupting a Joule-heating sweep at an intermediate bias should freeze a partially converted pattern in place, letting stacking domains be written in arbitrary shapes rather than only fully converted; this is a testable extension the paper does not perform.
  • The transition's irreversibility blocks stroboscopic pump–probe measurement, as the authors note, but a two-stage scheme — a train of heating pulses followed by a delayed electron probe — could still bracket the switching time, turning their single-pulse null result (a lower bound in the nanosecond range) into an actual measurement.
  • Because the estimated domain-wall pressures of 6–36 GPa straddle the previously reported ~22 GPa threshold, purely mechanical stress, such as bending or pressing the flake, should also drive ABC-to-ABA conversion at room temperature without global heating, connecting this work to earlier tip-based manipulation of stacking solitons.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. This manuscript reports experimental observations of a local, controlled transition from ABC (rhombohedral) to ABA (Bernal) stacking in few-layer graphene. Two methods are presented: Joule heating of an hBN-encapsulated FLG device, monitored by spatially resolved Raman 2D-peak mapping, and illumination with trains of femtosecond laser pulses in a transmission electron microscope, monitored by selected-area electron diffraction and dark-field imaging. The authors interpret the results as a thermally driven transition accompanied by motion of a domain wall, and they image a domain wall at roughly 9 nm resolution in dark-field mode.

Significance. If the central claim holds, the paper offers a practical route to locally engineer stacking order in few-layer graphene, which is relevant for creating in-plane heterostructures with tunable electronic properties. The results also provide insight into the transition mechanism, suggesting a thermally driven shear process. The paper's strengths include the combination of Raman and TEM characterization, the use of simulated diffraction patterns as a reference, and the direct dark-field visualization of a domain wall. The thermal interpretation is supported by the observation that single pulses do not induce the transition while pulse trains do, consistent with heat build-up.

major comments (3)
  1. [Sec. 2.2, Eq. (1), Supplemental Fig. S5] The conversion of the diffraction ratio R to an ABA fraction F_ABA uses a calibration from simulated trilayer (L=3) patterns, but the experimental FLG is about 2.5 nm thick (roughly 7 layers). The supplementary text states that for ABC stacking with L not a multiple of 3, the discriminating first-order peak at 4.7 nm^-1 is 'very weak' rather than absent, so the pure-trilayer baseline cannot be applied without an L-dependent recalibration. The measured pre-illumination R=0.019 already yields F_ABA≈0.038 for a region claimed to be entirely ABC, indicating the baseline is not known to the required accuracy. An error analysis or a layer-count-adjusted calibration is needed before the change to R=0.144 can be interpreted as a partial transition.
  2. [Sec. 2.2, Figs. 4d-e and 4j-k] The only post-train evidence for the partial transition is the scalar R obtained from selected-area diffraction; no dark-field image or Raman map of the same region after the pulse train is presented. The single-pulse dark-field controls in Fig. 4j-k show laser-induced contrast changes that the authors attribute to rippling, so a non-stacking contribution to R (e.g., from rippling, damage, or contamination) is a live alternative. Spatially resolved post-train data, or an explicit test ruling out non-stacking contributions, would be needed to substantiate the claim of a partial transition and the associated domain-wall motion.
  3. [Sec. 2.1, Fig. 2c] The Raman classification uses hard thresholds R<1.3 (ABC) and R>1.7 (ABA) without quoted uncertainties. The intermediate values, R between about 1.3 and 1.6, are interpreted as gradual partial transition and a shifting DW, but without error bars or a calibrated mixing model this quantitative interpretation is not firmly supported. Please provide error bars on R and a calibration for mixed stacking if the gradual-shift claim is to be made.
minor comments (5)
  1. [Sec. 2.1] The phrase 'ABS FLG' should be 'ABC FLG'.
  2. [Sec. 2.1, thermal model] The sentence describing the series resistors says 'one resistor (the ABC domain) having a resistance an order of magnitude higher than the other (the ABC domain)'; the second domain should be ABA.
  3. [Throughout] Several typographical errors are present, including 'indentify' (should be 'identify') and 'sheer movements' (should be 'shear movements').
  4. [Eq. (1)] The definition of R is not typeset clearly; a more explicit presentation of the ratio of summed intensities would improve readability.
  5. [Sec. 2.2] The authors note that the radial intensity profiles 'can only serve as an approximate guide'; this caveat should be reflected when drawing quantitative conclusions from the ratio R.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity; calibrated observables and an independent pressure comparison support the central claim, with only methodological self-citations.

full rationale

The paper's central claims are experimental: Raman maps show the 2D-peak ratio R=I3/I2 crossing its calibrated ABA/ABC thresholds progressively with applied bias, and electron diffraction shows R increasing from 0.019 to 0.144 after a laser pulse train, with dark-field imaging revealing a domain wall. These observables are calibrated against known or simulated ABA/ABC references (Raman thresholds in Sec. 2.1; Eq. 1 and the linear F_ABA formula in Sec. 2.2), which is standard calibration rather than circular reasoning. The authors explicitly caution that the radial intensity profiles are approximate and that the 4.7 nm^-1 peak is very weak for ABC stacking when the layer number is not a multiple of three (Supplemental Fig. S5), so the trilayer-based F_ABA conversion is a stated accuracy limitation, not a concealed input. The pressure and temperature estimates in Sec. 2.1 use a thermal-conductance parameter g fitted from a luminescence measurement at 8 V, but the transition voltages (3.5 V, 7.5 V, 9 V) are observed independently from Raman maps, and the resulting DW pressures are compared with an external literature value of ~22 GPa (Ref. 25), so the model is not being validated on the same data used to fit it. Self-citations (Refs. 20-22, 26-27; Supplemental Refs. 1, 5) concern sample preparation, the Joule-heating protocol, and the ultrafast electron microscope instrumentation; none supplies the load-bearing evidence for the stacking transition or the domain-wall motion. No equation or claim reduces by construction to its own inputs, and no uniqueness theorem or first-principles result is imported from the authors' prior work to force the conclusion. The finding is therefore a normal non-circular experimental report, with only minor methodological self-citation.

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

The central claim rests on empirically calibrated spectral and diffraction classifiers, a simplified 1D thermal model with a fitted conductance, and the assumption that the two stackings differ only in resistivity. These are not new physical entities but calibration and modeling choices that introduce uncertainty into the quantitative claims.

free parameters (4)
  • Raman stacking thresholds (R<1.3 ABC, R>1.7 ABA) = R=1.3 and R=1.7
    Empirical thresholds used to assign ABC versus ABA from the ratio I3/I2 of Lorentzian sub-peaks of the Raman 2D peak; no uncertainty or calibration statistics given.
  • Out-of-plane thermal conductance g = 4.3 x 10^3 W m^-2 K^-1
    Fitted from grey-body fit to luminescence at 8 V in the Joule heating device; used in Eq. S1 to compute temperature profiles and hence critical pressures.
  • Thermal expansion coefficient alpha = 2.8 x 10^-6 K^-1
    Fixed constant used in Eq. S2 to convert temperature rise to DW pressure; the paper notes the true value is temperature dependent.
  • Electron diffraction calibration constants (0.005, 0.444) = R_ABC=0.005, R_ABA=0.444
    Endpoints of the linear F_ABA mapping calibrated from simulated ABA and ABC trilayer diffraction patterns; experimental F_ABA values inherit these simulation assumptions.
assumptions (4)
  • domain assumption ABC and ABA stacked domains have identical specific heat capacity and thermal expansion coefficient; only resistivity differs.
    Stated in Supplemental Material Section 2; underpins the conclusion that resistive heating creates differential stress at the DW.
  • domain assumption The temperature distribution along the device is described by a 1D heat diffusion equation with both ends held at 300 K.
    Eq. S1; simplification that neglects 2D heat spreading and contact effects, directly used to compute DW pressures.
  • domain assumption Electron diffraction intensities are approximated by kinematic independent-atom scattering (no multiple scattering, no Debye-Waller factor).
    Supplemental Material Section 5; simulation of reference ABC and ABA patterns used to calibrate F_ABA.
  • domain assumption The phase transition is driven by compressive stress at the DW created by restricted thermal expansion.
    Proposed mechanism in Section 2.1 and Discussion; not directly measured, used to interpret the Joule heating results.

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Cite this review

Pith. "Pith review of Stacking transition in rhombohedral graphite." pith.science (2026). https://pith.science/paper/QMVPU5BP

@misc{pith2026190806284,
  author       = {Pith},
  title        = {Pith review of: Stacking transition in rhombohedral graphite},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/QMVPU5BP}},
  note         = {Machine review of arXiv:1908.06284}
}
read the original abstract

Few layer graphene (FLG) has been recently intensively investigated for its variable electronic properties defined by a local atomic arrangement. While the most natural layers arrangement in FLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) stacking characterized by a relatively high energy barrier can also occur. When both stacking occur in the same FLG device this results in in-plane heterostructure with a domain wall (DW). We show that ABC stacking in FLG can be controllably and locally turned into ABA stacking by two following approaches. In the first approach, Joule heating was introduced and the transition was characterized by 2D-peak Raman spectra at a submicron spatial resolution. The observed transition was initiated at a small region and then the DW controllably shifted until the entire device became ABA stacked. In the second approach, the transition was achieved by illuminating the ABC region with a train of laser pulses of 790 nm wavelength, while the transition was visualized by transmission electron microscopy in both diffraction and dark field modes. Also, with this approach, a DW was visualized in the dark-field imaging mode, at a nanoscale spatial resolution.

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Reference graph

Works this paper leans on

6 extracted references · 6 canonical work pages

  1. [1]

    Graphene hot-electron light bulb: incandescence from hBN -encapsulated g raphene in air,

    S. K. Son, C. Mullan, J. Yin, V. G. Kravets, A. Kozikov, S. Ozdemir, M. Alhazmi, M. Holwill, K. Watanabe, T. Taniguchi, D. Ghazaryan, K. S. Novoselov, V. I. Fal'ko, and A. Mishchenko, "Graphene hot-electron light bulb: incandescence from hBN -encapsulated g raphene in air," 2D Materials 5, 011006 (2018)

    work page 2018

  2. [2]

    Shabalin, Ultra-High Temperature Materials

    I. Shabalin, Ultra-High Temperature Materials. (Springer, 2016)

    work page 2016

  3. [3]

    The high temperature thermal expansion of graphite parallel to the hexagonal axis,

    B. T. Kelly, "The high temperature thermal expansion of graphite parallel to the hexagonal axis," Carbon 10, 435-438 (1972)

    work page 1972

  4. [4]

    Thermal expansion coefficients of graphite crystals,

    W. C. Mor gan, "Thermal expansion coefficients of graphite crystals," Carbon 10, 73 -79 (1972)

    work page 1972

  5. [5]

    Convergent beam electron holography for analysis of van der Waals heterostructures,

    T. Latychevskaia, C. R. Woods, Y. B. Wang, M. Holwill, E. Prestat, S. J. Haigh, and K. S. Novoselov, "Convergent beam electron holography for analysis of van der Waals heterostructures," Proceedings of the National Academy of Sciences 115, 7473–7478 (2018)

    work page 2018

  6. [6]

    NIST Electron Elastic -Scattering Cross -Section Database,

    A. Jablonski, "NIST Electron Elastic -Scattering Cross -Section Database," NIST Standard Reference Database 64 (2010)

    work page 2010

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