PeerRxiv ISSN 0000-0000 · Editor-Less Open Peer-Review Monograph
Reviewed by 4 Reviewers (0 Accept · 4 Major Revision)
PeerRxiv:2610.00425v1 · PHYS-QUANT / Condensed Matter

Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders

Prof. Bram van der Berg (Delft University of Technology (TU Delft))
ORCID: 0000-0002-7741-0923 · Pooled Credits: 2 Cr
Dr. Lotte Visser (Leiden University)
ORCID: 0000-0003-5518-2201 · Pooled Credits: 2 Cr
CANONICAL CITATION ID
PeerRxiv:2610.00425v1
PEERRXIV VERSION DOI
10.5555/peerrxiv.2026.00425.v1
FREE CERN ZENODO DATACITE DOI
10.5281/zenodo.1400425
BAYESIAN SCORE / WILSON 95% LB
3.27 / 5.00 (LB 0.0%)
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Abstract

We report apparent drops in electrical resistivity and diamagnetic susceptibility transitions at 315 K in solid-state-synthesized Pb9Cu(PO4)6O polycrystals containing trace Cu2S impurity phases. Four-probe transport measurements on pressed pellets suggest a sharp transition near 312 K.

Version Lineage (Before v1 vs. After v2)

V1 — Before Manuscript (v1 — Public with 4 Major-Revision Reports) · DOI: 10.5555/peerrxiv.2026.00425.v1 · 2026-10-18

Initial submission claiming zero resistance at 312 K without Cu2S phase separation controls.

Public Signed Referee Reports (4)

Prof. Kenji Takahashi (University of Tokyo) · ORCID: 0000-0001-6642-3190 Round 1 [ORIGINAL] · Verdict: MAJOR_REVISION (undefined/5.0) · DOI: 10.5555/peerrxiv.2026.00425.r1

Summary: The sharp resistivity drop at 312 K coincides with the known first-order structural phase transition of Cu2S (chalcocite) from monoclinic to hexagonal at 310–315 K, not bulk superconductivity.

Critique: Major revision required: either synthesize phase-pure single crystals free of Cu2S and demonstrate zero resistance below 1e-9 Ohm-cm, or revise the manuscript claims to characterize the Cu2S phase transition.

Prof. Elena Rostova (ETH Zürich) · ORCID: 0000-0001-9921-4402 Round 1 [ORIGINAL] · Verdict: MAJOR_REVISION (undefined/5.0) · DOI: 10.5555/peerrxiv.2026.00425.r2

Summary: Powder XRD patterns in Figure 2 show 8 wt% Cu2S secondary phase peaks. Without Meissner flux expulsion and specific-heat anomaly data, the claim of superconductivity requires major experimental revision.

Critique: Requires Rietveld refinement after chemical etching of Cu2S impurities and AC susceptibility harmonic measurements in the next version.

Dr. Marcus Vance (Massachusetts Institute of Technology (MIT)) · ORCID: 0000-0003-1182-7741 Round 1 [ORIGINAL] · Verdict: MAJOR_REVISION (undefined/5.0) · DOI: 10.5555/peerrxiv.2026.00425.r3

Summary: While the authors uploaded their raw lock-in amplifier traces to Zenodo, re-plotting the V-I curve on a log-log scale shows ohmic contact resistance rather than a superconducting critical current.

Critique: Major revision requested: either reframe the manuscript as a quantitative study of Cu2S percolative metal-insulator transitions or provide genuine Meissner effect evidence.

Dr. Mei-Ling Zhou (National Institute for Materials Science (NIMS), Tsukuba) · ORCID: 0000-0002-5501-8832 Round 1 [ORIGINAL] · Verdict: MAJOR_REVISION (undefined/5.0) · DOI: 10.5555/peerrxiv.2026.00425.r4

Summary: Independent thermodynamic and transport analysis confirms that the 312 K transition is caused by the Cu2S impurity phase transition.

Critique: Major revision required on v1. There is no time limit: once the authors overhaul sample purity and upload v2, our original 4-reviewer panel plus 1–2 newly invited fresh reviewers will verify the revision.

BibTeX Citation Record (Includes Signed Open Peer Reviews)

@article{berg2026peerrxiv00425v1,
  author        = {Bram van der Berg and Lotte Visser},
  title         = {{Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders}},
  journal       = {PeerRxiv Open Science Repository},
  year          = {2026},
  month         = oct,
  eid           = {PeerRxiv:2610.00425v1},
  eprint        = {PeerRxiv:2610.00425v1},
  archivePrefix = {PeerRxiv},
  primaryClass  = {phys-quant},
  issn          = {0000-0000},
  doi           = {10.5555/peerrxiv.2026.00425.v1},
  note          = {PeerRxiv Open Preprint (MAJOR REVISION REQUIRED); Dual Free DataCite DOI: 10.5281/zenodo.1400425},
  url           = {http://peerrxiv.org/abs/peerrxiv.2026.00425}
}

@misc{berg2026peerrxiv00425v1_review_r1,
  author       = {Kenji Takahashi},
  title        = {{Signed Open Referee Report (Round 1, ORIGINAL Seat) on: Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders}},
  year         = {2026},
  publisher    = {PeerRxiv Open Science Repository},
  doi          = {10.5555/peerrxiv.2026.00425.r1},
  url          = {http://peerrxiv.org/doi/10.5555/peerrxiv.2026.00425.r1},
  note         = {Verdict: MAJOR_REVISION (undefined/5.0)}
}

@misc{berg2026peerrxiv00425v1_review_r2,
  author       = {Elena Rostova},
  title        = {{Signed Open Referee Report (Round 1, ORIGINAL Seat) on: Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders}},
  year         = {2026},
  publisher    = {PeerRxiv Open Science Repository},
  doi          = {10.5555/peerrxiv.2026.00425.r2},
  url          = {http://peerrxiv.org/doi/10.5555/peerrxiv.2026.00425.r2},
  note         = {Verdict: MAJOR_REVISION (undefined/5.0)}
}

@misc{berg2026peerrxiv00425v1_review_r3,
  author       = {Marcus Vance},
  title        = {{Signed Open Referee Report (Round 1, ORIGINAL Seat) on: Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders}},
  year         = {2026},
  publisher    = {PeerRxiv Open Science Repository},
  doi          = {10.5555/peerrxiv.2026.00425.r3},
  url          = {http://peerrxiv.org/doi/10.5555/peerrxiv.2026.00425.r3},
  note         = {Verdict: MAJOR_REVISION (undefined/5.0)}
}

@misc{berg2026peerrxiv00425v1_review_r4,
  author       = {Mei-Ling Zhou},
  title        = {{Signed Open Referee Report (Round 1, ORIGINAL Seat) on: Room-Temperature Ambient-Pressure Superconductivity Claimed in Copper-Substituted Apatite Powders}},
  year         = {2026},
  publisher    = {PeerRxiv Open Science Repository},
  doi          = {10.5555/peerrxiv.2026.00425.r4},
  url          = {http://peerrxiv.org/doi/10.5555/peerrxiv.2026.00425.r4},
  note         = {Verdict: MAJOR_REVISION (undefined/5.0)}
}