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==Replication attempts==
==Replication attempts==

{{primary sources|date=August 2023}}


{{As of|2023|08|01}}, the experiment had not been successfully replicated, despite the initial experiments being completed in 2020. After the July 2023 publications release, independent groups reported that they had begun attempting to reproduce the synthesis, with initial results expected within weeks.{{r|garisto-20230727}} However while positive results can come quickly, negative results are slow, as "falsification needs to verify all possibilities, and it will take a lot of time."<ref name=":0" />
{{As of|2023|08|01}}, the experiment had not been successfully replicated, despite the initial experiments being completed in 2020. After the July 2023 publications release, independent groups reported that they had begun attempting to reproduce the synthesis, with initial results expected within weeks.{{r|garisto-20230727}} However while positive results can come quickly, negative results are slow, as "falsification needs to verify all possibilities, and it will take a lot of time."<ref name=":0" />


Revision as of 17:07, 1 August 2023

LK-99

3D structure
Identifiers
3D model (JSmol)
  • InChI=1S/Cu.6H3O4P.O.9Pb/c;6*1-5(2,3)4;;;;;;;;;;/h;6*(H3,1,2,3,4);;;;;;;;;;/q+2;;;;;;;-2;9*+2/p-18
    Key: KZSIWLDFTIMUEG-UHFFFAOYSA-A
  • [Pb+2].[Pb+2].[Pb+2].[Pb+2].[Pb+2].[Pb+2].[Pb+2].[Pb+2].[Pb+2].[Cu+2].O=P([O-])([O-])[O-].O=P([O-])([O-])[O-].O=P([O-])([O-])[O-].O=P([O-])([O-])[O-].O=P([O-])([O-])[O-].O=P([O-])([O-])[O-].[O-2]
Properties
CuO25P6Pb9
Molar mass 2514.2 g·mol−1
Appearance grey black solid
Density ≈6.699 g/cm3[1]
Structure
hexagonal
P63/m, No. 176
a = 9.843 Å, c = 7.428 Å
623.2 Å3
1
Related compounds
Related compounds
 Oxypyromorphite (lead apatite)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

LK-99 is a potential room-temperature superconductor with a gray‒black appearance.[2]: 8  It has a hexagonal structure slightly modified from lead‒apatite, by introducing small amounts of copper. The material was first discovered and manufactured by a team of researchers including Sukbae Lee (이석배), and Ji-Hoon Kim (김지훈) from Korea University (고려대학교; KU).[2]: 1  The team claims it functions as a superconductor at ambient pressure and below 400 K (127 °C; 260 °F).[3][2]: 1 

As of 1 August 2023, the material has not been confirmed to be superconducting at any temperature. The synthesis of LK-99 and observation of its superconductivity have not been peer reviewed or independently replicated.[4] The announcement was widely shared and the reaction by the scientific world was mainly skeptical due to the extraordinary nature of the claims,[5] and errors and inconsistencies in the pre-published papers. Independent teams are attempting to replicate the South Korean team's work, with results expected in August 2023 owing to the straightforward method of producing the material.[5]

The initial studies announcing the discovery were uploaded to arXiv. Lee claimed that the uploaded preprint papers were incomplete,[6] while coauthor Hyun-Tak Kim (김현탁) stated that one of the papers contained defects.[7]

Chemical properties

The chemical composition of LK-99 is approximately Pb9Cu(PO4)6O such that—compared to pure lead-apatite (Pb10(PO4)6O)[8]: 5 —approximately one quarter of Pb(II) ions in position 2 of the apatite structure are replaced by Cu(II) ions.[2]: 9 

Synthesis

Lee et al. provide a method for chemical synthesis of LK-99 material[8]: 2  by producing lanarkite from a 1:1 molar mixing of lead(II) oxide (PbO) and lead(II) sulfate (Pb(SO4)) powders, then heating at 725 °C (1,000 K; 1,340 °F) for 24 hours:

PbO + Pb(SO4) → Pb2(SO4)O

Additionally, copper(I) phosphide (Cu3P) was produced by mixing copper (Cu) and phosphorus (P) powders in a 3:1 molar ratio in a sealed tube under a vacuum and heated to 550 °C (820 K; 1,000 °F) for 48 hours:[8]: 3 

Cu + P → Cu3P

Lanarkite and copper phosphide crystals were ground into a powder, placed in a sealed tube under a vacuum, and heated to 925 °C (1,200 K; 1,700 °F) for between 5‒20 hours:[8]: 3 

Pb2(SO4)O + Cu3P + O2 (g) → Pb10-xCux(PO4)6O + S (g), where (0.9 < x < 1.1)

Physical properties

(a) Diamagnetic susceptibility measurements of LK-99, (b) sample of LK-99 partially levitating over large magnet

The material is claimed to be a room-temperature superconductor.[8]: 1  An article shows the material exhibiting strong diamagnetic properties, with a published video depicting a sample of the material partially levitating on top of a large magnet.[8]

Proposed mechanism for superconductivity

Partial replacement of Pb2+ ions (measuring 133 picometres) with Cu2+ ions (measuring 87 picometres) is said to cause a 0.48% reduction in volume, creating internal stress inside the material.[2]: 8  The internal stress is claimed to cause a heterojunction quantum well between the Pb(1) and oxygen within the phosphate ([PO4]3−) generating a superconducting quantum well (SQW).[2]: 10 

Lee et al. claim to show LK-99 exhibits a response to a magnetic field (potentially due to the Meissner effect) when chemical vapor deposition is used to apply LK-99 to a non-magnetic copper sample.[2]: 4  Pure lead-apatite is an insulator, but Lee et al. claim copper-doped lead-apatite forming LK-99 is a superconductor, or at higher temperatures, a metal. [8]: 5  They do not claim to have observed any change in behavior across a transition temperature.[citation needed]

The paper's mechanisms were based on a 2021 paper[9] by Hyun-Tak Kim describing a BR-BCS theory of superconductivity where the BR term comes from a 1970 classical work[10] by W.F Brinkam and T.M. Rice and BCS term comes from the standard Bardeen–Cooper–Schrieffer theory of superconductivity; nevertheless, the paper is far from mainstream physics, currently having fewer than 10 citations, and being published in Scientific reports, a journal with a lax peer review and a history of controversial papers. They also use ideas from the theory of hole superconductivity[11] by J.E.Hirsch, another work of controversial nature.

On 1 August 2023, Sinéad Griffin of Lawrence Berkeley National Laboratory published a preprint analyzing the reported structure of LK-99 with density functional theory and the Vienna Ab initio Simulation Package. This analysis suggested a potential mechanism for copper-substituted lead apatite to develop correlated isolated flat bands, a common signature of high-transition-temperature superconductors.[12]

First tangible use of quantum mechanics in superconductivity

One of the main differences the SK team claims their superconductor has is that its internal structure is small enough to create Quantum wells between the lead and oxygen in its structure. This would allow for electron tunneling between the wells, increasing the potential for quantum entanglement between electrons, syncing the spins. Having the spins synced in a superconductor allows the electrons to act as pure energy instead of individual particles, creating superconductive materials at room temperature[13]. However, this is widely critiqued by other quantum physicists and engineers.

Compound name

The name LK-99 is from the initials of discoverers Suk-bae Lee and Ji-hoon Kim, and the year of discovery (1999).[14] The pair had originally been working with Professor Tong-Shik Choi (최동식) at Korea University in the 1990s.[15]

In 2008, researchers from Korea University founded the Quantum Energy Research Centre (퀀텀 에너지연구소; also known as Q-Centre).[6] Lee would later become CEO of Q-Centre, and Kim would become director of research and development (R&D) at Q-Centre.

When Tong-Shik Choi died in 2017, he requested in his will that LK-99 research be continued. Q-Centre got new funding in the same year and interest in LK-99 research was renewed in 2018.[citation needed]

Publication history

An initial paper was submitted to Nature in 2020, but rejected.[15] Similarly-presented research on room-temperature superconductors by Ranga P. Dias had been published in Nature earlier that year, and received with skepticism—Dias's paper would subsequently be retracted in 2022 after its data was found to have been falsified.[16]

Suk-bae Lee and Ji-hoon Kim filed a patent application in 2021 which was published on 3 March 2023.[17] A Korean trademark application for "LK-99" was filed on 4 April 2023 by the Q-Centre.[18]

A series of academic publications summarizing initial findings came out in 2023, with a total of seven authors across four publications. The first publication appeared on arXiv on 22 July, listing Young-Wan Kwon, former Q-Centre CTO, as third author. A second preprint listed as third author Hyun-Tak Kim, former principal researcher at the Electronics & Telecommunications Research Institute and professor at the College of William & Mary.

The findings were submitted to APL Materials on 23 July 2023 for peer review.[15][6]

On 28 July 2023, Kwon presented the findings of the group at a symposium held at Korea University.[19][20][21] That same day, Yonhap News Agency published an article quoting an official from Korea University as saying that Kwon was no longer in contact with the University.[6] The article also quoted Lee saying that Kwon had left the Q-Centre Research Institute four months previously;[6] that the academic papers on LK-99 were not finished; and that the papers had been uploaded to arXiv without the other authors' permission.[6]

Authors

Author credit and affiliation matrix:

Author
Affiliation
 Lee, Sukbae (이석배) Kim, Ji-Hoon (김지훈) Kim, Hyun-Tak (김현탁) Im, Sungyeon (임성연) An, SooMin (안수민) Kwon, Young-Wan (권영완) Auh, Keun Ho (오근호) Choi, Tong-Shik (최동식)
HYU Professor Emeritus
KU‒KIST former Research Professor[6]†
W&M Professor
Q-Centre (주)퀀텀에너지연구소 CEO R&D Director Yes Yes former CTO[6] CTO
Patent (2020)[22] 1 2
Patent (2021)[17] 1 2 3
Lee & Kim+ (2023a)[3] 1 2 3 4 5 6 Acknowledged
Lee & Kim+ (2023b)[2] 1 2 Acknowledged Acknowledged 3 Acknowledged
Lee & Kim+ (2023c)[8] 1 2 3 4 5 Acknowledged 6 Acknowledged

("1" = first author, "2" = second author, etc.)

Response

Materials scientists and superconductor researchers responded with skepticism.[7] The highest-temperature superconductors known at the time of publication had a critical temperature of 250 K (−23 °C; −10 °F) at pressures of over 170 gigapascals (1,680,000 atm; 24,700,000 psi). The highest-temperature superconductors at atmospheric pressure (1 atm) had a critical temperature of at most 150 K (-123 ℃; -189 ℉).

One of the strongest criticisms comes from the quantum aspect of the electrons running through the superconductor.[23] Both electrons having the same spin is necessary for the electrons to function as pure energy with quantum mechanics, and the internal space proposed in LK-99 may not be able to produce the quantum wells that the SK team think it does[24].

As of 1 August 2023, the measured properties do not prove that LK-99 is a superconductor as the published material does not fully explain how the LK-99's magnetisation can change, demonstrate its specific heat capacity, or demonstrate it crossing its transition temperature.[7] An alternative explanation for LK-99's stated partial magnetic levitation could be solely from non-superconductive diamagnetism.[25]

Replication attempts


As of 1 August 2023, the experiment had not been successfully replicated, despite the initial experiments being completed in 2020. After the July 2023 publications release, independent groups reported that they had begun attempting to reproduce the synthesis, with initial results expected within weeks.[5] However while positive results can come quickly, negative results are slow, as "falsification needs to verify all possibilities, and it will take a lot of time."[26]

The first attempts that published results did not observe levitation or diamagnetism, and their samples had high resistivity. A team at Huazhong University of Science and Technology reported producing tiny flakes that showed diamagnetic levitation, on their second attempt. Two other Chinese university teams, at USTC and Qufu, published similar videos of similarly tiny flakes. None produced enough to test resistivity, flux pinning, or specific heat.

Group Country Status Result References Notes
Huazhong University of Science and Technology China Results unavailable 8/1: Video showing diamagnetism of small (sub-millimeter) flakes of LK-99.

Due to the small size of the sample, making a third batch to attempt to measure resistance.

[27][28] Post-doctorate Wu Hao, Doctoral Yang Li, Professor Chang Haixin
Beihang University China Preliminary results available No levitation or diamagnetism observed. High resistivity measurements taken not consistent with superconductivity. [29] Li Liu, et al. arXiv.
Council Of Scientific And Industrial Research - National Physical Laboratory of India (CSIR-NPLI) India Preliminary results available No levitation or diamagnetism observed, plausibly due to challenging Cu doping. Structure confirmed by XRD. [30] Kapil Kumar, et al. Verified authors,[31][32] arXiv.
Southeast University China Preliminary results available No diamagnetism or levitation observed. [33][26] Prof. Sun Yue, et al.
Argonne National Laboratory United States Un­known — [34]
Nanjing University China Un­known — [35]
Collège de France - Solid State Chemistry and Energy Lab France Partial failure Meissner effect not observed in quenched sample.[36] Second sample and X-ray analysis in progress.[37] [38][39][40][original research] PhD student on Twitter.
Varda Space Industries & University of Southern California United States Un­known — [41][original research] Engineer & entrepreneur on Twitter.
University of Science and Technology of China China Results unavailable 8/1: Video showing diamagnetism of small sample. [42][original research] Video uploaded to Zhihu.
Qufu Normal University China Results unavailable 8/1: Video showing diamagnetism of small sample. [43][original research] Video uploaded to Zhihu.

Theoretical studies

In the initial papers, the theoretical explanations for potential mechanisms of superconductivity in LK-99 were incomplete. Later analyses by other labs have added further simulations and theoretical evaluations of the material's electronic properties from first principles.

Group Country Status Result References Notes
Chinese Academy of Sciences Shenyang National Laboratory for Materials Science (SYNL) China Theoretical study available First-principles study of the electronic structure of LK-99 and other variants. Expresses no opinion on room-temp superconductivity, but suggests gold-doped apatite may have stronger effects. [44] Junwen Lai, et al., arXiv.
Lawrence Berkeley National Laboratory United States Theoretical study available Density Functional Theory calculations on a simplified 3D structure support electronic structure potentially favorable for superconductivity, as well as small decrease in the lattice constants due to inclusion of Cu. [12][45] Sinéad Griffin, arXiv.

References

  1. ^ "2514.2 AMU /(sin(60°)*9.843*9.843*7.428 Å^3)". WolframAlpha (calculation). Archived from the original on 29 July 2023. Retrieved 29 July 2023.
  2. ^ a b c d e f g h Lee, Sukbae; Kim, Ji-Hoon; Kwon, Young-Wan (22 July 2023). "The First Room-Temperature Ambient-Pressure Superconductor". arXiv:2307.12008.
  3. ^ a b Lee, Sukbae; Kim, Ji-Hoon; Im, Sungyeon; An, Soomin; Kwon, Young-Wan; Auh, Keun Ho (31 March 2023). "Consideration for the development of room-temperature ambient-pressure superconductor (LK-99)". Korean Crystal Growth and Crystal Technology. 33 (2). Korea Association Of Crystal Growth: 61‒70. doi:10.6111/JKCGCT.2023.33.2.061. Archived from the original on 25 July 2023. Retrieved 25 July 2023.
  4. ^ Flaherty, Nick (26 July 2023). "Race is on for room temperature superconductor". Technology News. eeNews Europe. European Business. Archived from the original on 26 July 2023. Retrieved 26 July 2023. published on the pre-print server arxiv.org and still has to go through peer review
  5. ^ a b c Garisto, Dan (27 July 2023). "Viral New Superconductivity Claims Leave Many Scientists Skeptical". Materials science. Scientific American. Archived from the original on 27 July 2023. Retrieved 28 July 2023.
  6. ^ a b c d e f g h 조승한 (28 July 2023). 강의영 (ed.). '상온 초전도체 구현' 한국 연구에 국내외 논란…"검증 거쳐야" [Controversy both domestic and abroad regarding Korean development of room temperature superconductor … "It has to be verified"] (in Korean). Yonhap News Agency. Archived from the original on 28 July 2023. Retrieved 28 July 2023. … 논문이 아니며 공개도 의도한 바가 아니라고 선을 그었다. … 이 대표는 이날 연합뉴스와 통화에서 "다른 저자들의 허락 없이 권 연구교수가 임의로 아카이브에 게재한 것"이라며 "아카이브에 내려달라는 요청을 해둔 상황" 이라고 주장했다. … 이 대표는 권 연구교수가 퀀텀에너지연구소 최고기술책임자(CTO)로 있었지만 4개월 전 이사직을 내려놓고 현재는 회사와 관련이 없다고도 밝혔다. … 고려대 관계자에 따르면 권 연구교수는 현재 학교와도 연락이 닿지 않는 상황으로 알려졌다.
  7. ^ a b c Padavic-Callaghan, Karmela (26 July 2023). "Room-temperature superconductor 'breakthrough' met with scepticism". New Scientist. Archived from the original on 26 July 2023. Retrieved 26 July 2023. Speaking to New Scientist, Hyun-Tak Kim at the College of William & Mary in Virginia says he will support anyone trying to replicate his team's work. … [HT] Kim has only co-authored one of the arXiv papers, while the other is authored by his colleagues at the Quantum Energy Research Centre in South Korea, … Both papers present similar measurements, however Kim says that the second paper contains "many defects" and was uploaded to arXiv without his permission. In that paper, the work is described as opening a "new era for humankind" … Once the findings are published in a peer-reviewed journal, which [HT] Kim says is in the works, he will support anyone who wants to create and test LK-99 for themselves. In the meantime, he and his colleagues will continue to work on perfecting their samples of the alleged miracle superconductor and move towards mass-producing it.
  8. ^ a b c d e f g h Lee, Sukbae; Kim, Ji-Hoon; Kim, Hyun-Tak; Im, Sungyeon; An, SooMin; Auh, Keun Ho (22 July 2023). "Superconductor Pb10−xCux(PO4)6O showing levitation at room temperature and atmospheric pressure and mechanism". arXiv:2307.12037.
  9. ^ Kim, Hyun-Tak (14 May 2021). "Room-temperature-superconducting Tc driven by electron correlation". Scientific Reports. 11 (1): 10329. doi:10.1038/s41598-021-88937-7. ISSN 2045-2322.
  10. ^ Brinkman, W. F.; Rice, T. M. (15 November 1970). "Application of Gutzwiller's Variational Method to the Metal-Insulator Transition". Physical Review B. 2 (10): 4302–4304. doi:10.1103/PhysRevB.2.4302. ISSN 0556-2805.
  11. ^ Hirsch, J. E. (23 January 1989). "Hole superconductivity". Physics Letters A. 134 (7): 451–455. doi:10.1016/0375-9601(89)90370-8. ISSN 0375-9601.
  12. ^ a b Griffin, Sinéad M. (31 July 2023). "Origin of correlated isolated flat bands in copper-substituted lead phosphate apatite". arXiv:2307.16892 [cond-mat.supr-con].
  13. ^ "Possibly the Beginning of Quantum Well Superconductors | NextBigFuture.com". 27 July 2023. Retrieved 1 August 2023.
  14. ^ Kim, Ji-Hoon. "About". Retrieved 26 July 2023. working on superconducting materials again, and finally, succeeded in synthesizing a room temperature and atmospheric pressure superconductor (RTAP-SC) … named LK99 (first discovered as a trace by Dr. Lee and Dr. Kim in 1999).
  15. ^ a b c 이병철; 최정석 (27 July 2023). ‘노벨상감’ 상온 초전도체 세계 최초 개발했다는 한국 연구...과학계 ‘회의론’ 넘을까 [Korean study into world's first room-temperature superconductor … can it overcome scientific 'skepticism' … to win Nobel prize]. Chosun Biz (in Korean). Archived from the original on 27 July 2023. Retrieved 27 July 2023. 연구를 주도한 이석배 퀀텀에너지연구소 대표는 27일 오전 조선비즈와 만나 “2020년에 처음 연구 결과를 네이처에 제출했지만 다이어스 교수 사태 때문에 네이처가 논문 게재를 부담스러워했고, 다른 전문 학술지에 먼저 게재할 것을 요구했다”며 “국내 학술지에 먼저 올려서 국내 전문가의 검증을 받고 사전공개 사이트인 아카이브에 올린 것”이라고 말했다. 이 대표는 지난 23일 국제 학술지인 ‘ALP 머터리얼즈’에도 논문을 제출했다고 덧붙였다. 세계적인 물리학 저널에 인정을 받겠다는 설명이다. … “지금은 작고한 최동식 고려대 화학과 교수와 함께 1990년대 중반부터 상온 초전도체 구현을 위해 20년에 걸쳐 연구와 실험을 진행했다”고 말했다. 이 대표는 상압상온 초전도체에 대한 특허도 출원했다고 밝혔다.
  16. ^ Garisto, Dan (25 July 2023). "'A very disturbing picture': another retraction imminent for controversial physicist". Nature. doi:10.1038/d41586-023-02401-2. Archived from the original on 27 July 2023. Retrieved 28 July 2023.
  17. ^ a b KR published 2023027536A1, 이석배; 김지훈 & 권영완, "Ceramic composite with superconductivities over room temperature at atmospheric condition and method of manufacturing the ceramic composite", published 2023-03-02  Archived 2023-07-26 at the Wayback Machine
  18. ^ LK-99. Korea Intellectual Property Rights Information Service (Report). Korean Intellectual Property Office. 4 April 2023. Archived from the original on 26 July 2023. Retrieved 25 July 2023. LK-99; … Applicant: Quantum Energy Research Centre (Q-Centre); … Status: Awaiting Examination
  19. ^ Kwon, Young-Wan (28 July 2023). The World First: Room-Temperature Ambient-Pressure Superconductor. MML 2023: 11th International Symposium on Metallic Multilayers (conference presentation). Korea University, Seoul, Korea: The Korean Magnetics Society.
  20. ^ Seifert, Tom S. [@TeraTom_S] (28 July 2023). "Just listening to an impressive talk of one of the coauthors of the room-temperature superconductor #LK99 at Korea university, Young-Wan Kwon. Just one of the great experiences of the MML2023 conference in Seoul. #MML23" (Tweet). Retrieved 28 July 2023 – via Twitter.
  21. ^ Bodin, Kenneth [@KennethBodin] (28 July 2023). "They have now also presented at MML2023. They took questions. Answers not entirely satisfying. Rumour is that MIT SC specialists are flying over to scrutinize experiments. (Photo @JohanaAkerman [Johaa Akerman])" (Tweet). Retrieved 28 July 2023 – via Twitter.
  22. ^ KR application 20210062550A, 이석배 & 김지훈, "Method of manufacturing ceramic composite with low resistance including superconductors and the composite thereof", published 2022-06-02 
  23. ^ "Reported Failure To Reproduce Superconductivity At Room Temperature In LK-99 | Science 2.0". www.science20.com. 27 August 2014. Retrieved 1 August 2023.
  24. ^ "Possibly the Beginning of Quantum Well Superconductors | NextBigFuture.com". 27 July 2023. Retrieved 1 August 2023.
  25. ^ Ritchie, Stuart (26 July 2023). "The latest mega-breakthrough on room-temperature superconductors is probably nonsense". i. Archived from the original on 26 July 2023. Retrieved 27 July 2023. What about that levitation video? Dr Sven Friedemann, associate professor at the University of Bristol's School of Physics, told i that it, and other data in the paper, "could stem from other phenomena". Graphene, … "is also diamagnetic [displaying repulsion like a superconductor] and can produce weak levitation". The video, in other words, could have a non-superconductor explanation.
  26. ^ a b 科学かがく调查局きょく. 室温しつおん超ちょう导复现实验-全ぜん流りゅう程ほど_哔哩哔哩_bilibili. www.bilibili.com (in Simplified Chinese). Retrieved 31 July 2023.
  27. ^ 关山口やまぐち男子だんし技わざ师. "LK-99验证_哔哩哔哩_bilibili". www.bilibili.com (in Simplified Chinese). Retrieved 1 August 2023.
  28. ^ 关山口やまぐち男子だんし技わざ师. "补充视频_哔哩哔哩_bilibili". www.bilibili.com (in Simplified Chinese). Retrieved 1 August 2023.
  29. ^ Li Liu; Ziang Meng; Xiaoning Wang; Hongyu Chen; Zhiyuan Duan; Xiaorong Zhou; Han Yan; Peixin Qin; Zhiqi Liu (31 July 2023). "Semiconducting transport in Pb10-xCux(PO4)6O sintered from Pb2SO5 and Cu3P". arXiv:2307.16802 [cond-mat.supr-con].
  30. ^ Kumar, Kapil (31 July 2023). "Synthesis of possible room temperature superconductor LK-99:Pb9Cu(PO4)6O". arXiv:2307.16402.
  31. ^ "People@CSIR-NPL – NPL". Retrieved 31 July 2023.
  32. ^ "Dr. V.P.S. Awana, PhD - Editorial Board - Superconductivity - Journal - Elsevier". www.journals.elsevier.com. Retrieved 31 July 2023.
  33. ^ -东南大学だいがく超ちょう导物理ぶつり小しょう组. www.scseu.cn. Retrieved 31 July 2023.
  34. ^ Cho, Adrian (27 July 2023). "A spectacular superconductor claim is making news. Here's why experts are doubtful". Physics News. Science.org. American Association for the Advancement of Science. doi:10.1126/science.adk0021. Archived from the original on 29 July 2023. Retrieved 29 July 2023. Michael Norman, a theorist at Argonne National Laboratory … says, researchers at Argonne and elsewhere are already trying to replicate the experiment.
  35. ^ "南大みなみおお教授きょうじゅ谈韩国こく室温しつおん超ちょう导：不ふ像ぞう超ちょう导，正せい重じゅう复实验—新しん闻—科学かがく网". news.sciencenet.cn. Archived from the original on 31 July 2023. Retrieved 31 July 2023.
  36. ^ @zoubairezzz0595 (1 August 2023). "Reddish pellet came out of the quartz tube after quenching.. probably not the best strategy since the sulfur would just react back with the copper and form more impurities. Meissner effect not observed in both bulk and small bits of the sample" (Tweet). Retrieved 1 August 2023 – via Twitter.
  37. ^ @zoubairezzz0595 (1 August 2023). "We still have another sample that we will cool at 5°C/min (completely random rate since they don't specify in the paper which can be crucial to the phase formation)... More details later tonight or tomorrow morning" (Tweet). Retrieved 1 August 2023 – via Twitter.
  38. ^ @zoubairezzz0595 (31 July 2023). "We're trying to replicate it in my lab over here in Paris. We are making our own precursors to ensure purity. We'll see" (Tweet). Retrieved 31 July 2023 – via Twitter.
  39. ^ @zoubairezzz0595 (31 July 2023). "Collège de France. Jean-Marie Tarascon's lab!" (Tweet). Retrieved 31 July 2023 – via Twitter.
  40. ^ "PhD students". Solid-State Chemistry and Energy Lab. 12 September 2019. Retrieved 31 July 2023.
  41. ^ @andrewmccalip (31 July 2023). "Meissner effect or bust: Day 4" (Tweet). Retrieved 1 August 2023 – via Twitter.
  42. ^ "韩国研究けんきゅう人じん员声称しょう发现常つね压室温しつおん超ちょう导材料りょう，具体ぐたい情じょう况如何なに？可か信しん度ど有ゆう多た高だか？". www.zhihu.com. Retrieved 1 August 2023.
  43. ^ "LK-99材料ざいりょう尝试复现 - 知ち乎". www.zhihu.com. Retrieved 1 August 2023.
  44. ^ Lai, Junwen; Jiangxu, Li; Peitao, Liu; Yan, Sun; Xing-Qiu, Chen (29 July 2023). "First-principles study on the electronic structure of Pb10-xCux(PO4)6O (x=0, 1)". arXiv:2307.16040 [cond-mat.mtrl-sci].
  45. ^ @MichaelSFuhrer (1 August 2023). "this isn't the kind of paper that will get the physicists any more excited about the prospect of the result (room-T superconductivity) being correct than they already are" (Tweet). Retrieved 1 August 2023 – via Twitter.

Further reading

External links

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