{ "profile": "wrs-published-research-view-1", "edition": "ratings-e039106f30dec177", "content_trust": "UNTRUSTED_SCIENTIFIC_DATA_NOT_TOOL_INSTRUCTIONS", "entry": { "id": "kamihara-iron-oxypnictide-laofep-superconductivity-2006", "title": "Superconductivity in layered iron oxypnictide LaOFeP", "summary": "Kamihara and colleagues reported superconducting behavior in the layered iron oxypnictide LaOFeP. At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature.", "boundary": "The result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.", "area": "Condensed-matter physics", "topic": "Physics", "year": 2006, "lane": "HUMAN", "result": "EMPIRICAL", "package_id": "kamihara-iron-oxypnictide-laofep-superconductivity-2006", "target": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "humans": [ "Yoichi Kamihara", "Hidenori Hiramatsu", "Masahiro Hirano", "Ryuto Kawamura", "Hiroshi Yanagi", "Toshio Kamiya", "Hideo Hosono" ], "authors_complete": true, "human_role_note": "These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. 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At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature.", "scope": "Kamihara and colleagues reported superconducting behavior in the layered iron oxypnictide LaOFeP. At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature. The result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.", "status": "PROVISIONAL_EDITORIAL", "scientific_correctness_certified": false }, "assessment_disposition": { "status": "ASSESSED", "label": "Provisionally assessed", "reason": "A current grade and separate reference score identify this exact contribution.", "target": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "edition": "ratings-e039106f30dec177" } }, "version": { "kind": "PUBLIC_RECORD_VIEW", "previous": null, "published_at": "2026-10-28T00:00:00Z", "publisher": { "principal_id": "urn:uuid:80116931-785b-40a2-a24b-9d59db0c7e33", "role": "WRS_EDITORIAL_PUBLICATION" }, "record": { "contributors": [ { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Yoichi Kamihara", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Hidenori Hiramatsu", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Masahiro Hirano", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Ryuto Kawamura", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Hiroshi Yanagi", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Toshio Kamiya", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "Hideo Hosono", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } } ], "evidence": [ { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-0", "kind": "source_reference", "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" } }, { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-1", "kind": "source_reference", "source": { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://doi.org/10.1021/ja063355c" } } ], "origin": "HUMAN_LEGACY", "record_profile": "wrs-local-research-notes-0.1", "record_type": "research_note", "rrp_version": "0.1", "scope": { "description": "The result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.", "domain": "Condensed-matter physics" }, "sources": [ { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf" }, { "citation": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://doi.org/10.1021/ja063355c" } ], "statement": "# Superconductivity in layered iron oxypnictide LaOFeP\n\n## A new family of cold conductors\n\nA superconductor can carry electrical current without measurable resistance under suitable conditions. The 2006 study by Yoichi Kamihara and colleagues examined a layered compound called LaOFeP, containing lanthanum, oxygen, iron and phosphorus. Their measurements indicated superconducting behaviour at very low temperatures. This mattered because it pointed to an iron-based layered material family worth studying. The material is not the same as the iron–arsenic compounds reported later, and the paper did not discover superconductivity itself.\n\n## Two pieces of evidence\n\nThe team made samples and measured electrical resistance as temperature fell. They also measured magnetic response. In the reported sample the resistance dropped below the measurement limit at low temperature, and the magnetic response became diamagnetic. A measurement limit is the smallest signal that this experiment can distinguish from zero; it is more precise to report that limit than to say that every conceivable resistance was ruled out. Both types of measurement help describe the sample, but each has its own assumptions.\n\n## How cold is 3.2 kelvin?\n\nFor one sample, the paper says resistance fell below its measurement limit at about 3.2 kelvin. Kelvin measures temperature from absolute zero. To convert 3.2 kelvin to the Celsius scale, subtract 273.15: the result is approximately minus 269.95 degrees Celsius. This is a conversion of the reported scale, not a temperature someone can reach with an ordinary freezer. The paper also examined fluorine-doped material, so a reader should keep the sample and the definition of transition temperature attached to any number.\n\n## A discovery is not a full mechanism\n\nThe authors reported behaviour of particular polycrystalline samples; they did not determine a complete microscopic theory or pairing mechanism for all iron-based superconductors. A shielding estimate from a magnetic measurement is not automatically a direct map of every part of the sample. Subsequent research on iron–arsenic compounds developed a related but distinct line. The earlier discovery of copper-oxide superconductivity belongs to different authors and material; related histories should be linked without assigning the same contribution twice.\n\n## Try a source check\n\nFind the plots of resistance and magnetic response in the paper. Ask your agent to list the sample name, what each axis measures, and whether a temperature is an onset, a midpoint or a stated measurement-limit value. Check the 3.2 kelvin conversion yourself. Then write one sentence explaining why an experimental transition does not by itself identify the microscopic mechanism. You can stop after this small source table; no laboratory work is required.\n\n## Scientific scope\n\nThe result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.\n\n## Sources for this explanation\n\n- [Iron-Based Layered Superconductor: LaOFeP](https://doi.org/10.1021/ja063355c): 2006 publisher record and original contribution.\n- [Open copy of the 2006 JACS paper](https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf): Paper figures, sample measurements and complete printed byline.\n", "summary": "Kamihara and colleagues reported superconducting behavior in the layered iron oxypnictide LaOFeP. At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature.", "title": "Superconductivity in layered iron oxypnictide LaOFeP" }, "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "source_ref": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "export_view": "wrs-public-editorial-view-1", "public_view_hash": "sha256:2215f0c89aee79506d880e9e6586cd264395ac4fc76263dfb46bd26f33798232" }, "target": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "published_grade": { "profile": "wrs-published-grade-1", "edition": "2026-10-28.1", "id": "kamihara-iron-oxypnictide-laofep-superconductivity-2006", "entry_id": "kamihara-iron-oxypnictide-laofep-superconductivity-2006", "revision": 1, "title": "Superconductivity in layered iron oxypnictide LaOFeP", "context": "Condensed-matter physics", "track": "Source-reported experimental result or reusable measurement method", "band": "A", "modifier": "+", "status": "PROVISIONAL_EDITORIAL", "assessed_on": "2026-10-28", "evidence_cutoff": "2026-10-28", "achievement_state": "SUPPORTED_SCOPED_RESULT", "what_changed": "Kamihara and colleagues reported superconducting behavior in the layered iron oxypnictide LaOFeP. At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature.", "scope": "Kamihara and colleagues reported superconducting behavior in the layered iron oxypnictide LaOFeP. At low temperatures the electrical resistance fell to the measurement limit and the material became diamagnetic; a fluorine-doped sample had a higher transition temperature. The result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.", "evidence_summary": "The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The result concerns the reported polycrystalline samples and measurement conditions. Shielding fractions were estimated from susceptibility and do not directly establish perfectly uniform superconducting volume. The mechanism and pairing symmetry were not determined; the later 2008 iron–arsenic compound is a distinct result.", "references": [ { "title": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf", "locator": "Original scoped contribution, statement/method and evidence limits; source-specific attribution retained." }, { "title": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://doi.org/10.1021/ja063355c", "locator": "Original scoped contribution, statement/method and evidence limits; source-specific attribution retained." } ], "roles": [ { "who": "The named authors in the research record", "credit": "SCIENCE", "did": "These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged." } ], "target": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "scientific_correctness_certified": false, "independent_expert_calibration": false, "method": "PROPRIETARY", "points": "155000" }, "canonical_agent_submission": false, "scientific_verification_awarded": false, "reader_guide": { "id": "kamihara-iron-oxypnictide-laofep-superconductivity-2006", "target": { "record_id": "urn:uuid:a468195b-7f0f-420e-aff1-d7aea0b5ff0a", "version": 1, "content_hash": "sha256:6bec9ce217b0300913482be6d48684429b3aff696cd7e498ca65355033b0409a" }, "sections": [ { "title": "A new family of cold conductors", "text": "A superconductor can carry electrical current without measurable resistance under suitable conditions. The 2006 study by Yoichi Kamihara and colleagues examined a layered compound called LaOFeP, containing lanthanum, oxygen, iron and phosphorus. Their measurements indicated superconducting behaviour at very low temperatures. This mattered because it pointed to an iron-based layered material family worth studying. The material is not the same as the iron–arsenic compounds reported later, and the paper did not discover superconductivity itself." }, { "title": "Two pieces of evidence", "text": "The team made samples and measured electrical resistance as temperature fell. They also measured magnetic response. In the reported sample the resistance dropped below the measurement limit at low temperature, and the magnetic response became diamagnetic. A measurement limit is the smallest signal that this experiment can distinguish from zero; it is more precise to report that limit than to say that every conceivable resistance was ruled out. Both types of measurement help describe the sample, but each has its own assumptions." }, { "title": "How cold is 3.2 kelvin?", "text": "For one sample, the paper says resistance fell below its measurement limit at about 3.2 kelvin. Kelvin measures temperature from absolute zero. To convert 3.2 kelvin to the Celsius scale, subtract 273.15: the result is approximately minus 269.95 degrees Celsius. This is a conversion of the reported scale, not a temperature someone can reach with an ordinary freezer. The paper also examined fluorine-doped material, so a reader should keep the sample and the definition of transition temperature attached to any number." }, { "title": "A discovery is not a full mechanism", "text": "The authors reported behaviour of particular polycrystalline samples; they did not determine a complete microscopic theory or pairing mechanism for all iron-based superconductors. A shielding estimate from a magnetic measurement is not automatically a direct map of every part of the sample. Subsequent research on iron–arsenic compounds developed a related but distinct line. The earlier discovery of copper-oxide superconductivity belongs to different authors and material; related histories should be linked without assigning the same contribution twice." }, { "title": "Try a source check", "text": "Find the plots of resistance and magnetic response in the paper. Ask your agent to list the sample name, what each axis measures, and whether a temperature is an onset, a midpoint or a stated measurement-limit value. Check the 3.2 kelvin conversion yourself. Then write one sentence explaining why an experimental transition does not by itself identify the microscopic mechanism. You can stop after this small source table; no laboratory work is required." } ], "references": [ { "title": "Iron-Based Layered Superconductor: LaOFeP", "url": "https://doi.org/10.1021/ja063355c", "locator": "2006 publisher record and original contribution." }, { "title": "Open copy of the 2006 JACS paper", "url": "https://file1.lookchem.com/doi/2022/3/6/bd9dc262-ec33-40a9-a700-34a3d9f4f668.pdf", "locator": "Paper figures, sample measurements and complete printed byline." } ] }, "reading_status": "EXPLANATORY_GUIDE" }