LK99 is the material that South Korean researchers claimed in early 2023 was a room temperature superconductor. The South Korean Researcher will be reporting new work in two months (March 4, 2024) at the APS conference. The patents and the original papers described superconducting low level electrical resistance for thin film versions of LK99. There were a lot of negative experiments from researchers who made bulk samples of LK99. The negative papers never made thin film and never wrote about trying to make thin film LK99.
There were also many positive LK99 science papers based upon computer simulation mainly using DFT (Density Function Theory).
There are two new separate experimental papers from China with strongest experimental evidence supporting the confirmation of the original korean work.
A large portion of the scientific community and public have turned against LK99. A room temperature superconductor is VERY hard work. The original cuprate superconductors had difficult replication until the YCBO formulation was discovered.
Hopefully, the two new chinese experimental will get people to realize that they vastly underestimated the effort to do LK99. People will see that they made a mistake in trying to go scorched earth over anyone trying to do work on LK99. This is science and it can be difficult and unreliable making something as remarkable as room temperature superconductors.
Prof. Kwon & Kim came out of Q-centre and started running a new company named CCS. CCS hosted the first business briefing for institutional investors on December 18th.
JH Kim, the heroic experimental chemist (the K, in LK-99), is no longer part of the team, leaving Lee as the principal author from Quantum Energy Korea
* The compound from Aug has been characterized further, no longer a mere lead apatite, but now PCPOSOS, with substitutions of Sulphur for Oxygen in some positions
* They don’t even claim the LK-99 name anymore (because that would, uh.. refer to a different compound)
* However, the team has confirmed Type-II superconductivity at room temperature and pressure, confirmed the Meissner effect, explained the partial levitation seen (it’s because the critical magnetic field that knocks out the superconductive effect is close enough that normal variation in magnetic field strength trigger the threshold)
What happened to JH Kim?
> In November he pops up joining the board of a startup called CCS along with JH Kwon
> Kwon, remember, is the Korea University professor who jumped the gun on the arxiv release, was fired, showed up as a last minute guest to the Minerals and Multi Metallic Materials Conference In Seoul, and generally acted as the spoiler in the last season
> So JH Kim seems to have left Quantum, to work alongside Kwon at the new company
South China University of Technology published experimental support for LK99 (lead apatite variant). The South China University of Technology team has 2 samples both created by accident which show superconductive effects, but continue to try to figure out a consistent manufacture.
Two China teams (Beijing) and South China joined up for another experimental paper. They each created two different samples and then replicated the other joined teams sample. There is replication happening.
Happy LK-99 New Year
Recap: After capturing the zeitgeist during a slow news summer between GPT-4 and the OpenAI board drama, LK-99 enthusiasts faded into embarrassed obscurity normally reserved for NFT owners and Tom Brady fans.
But neither science nor history care for your…
— Ate-a-Pi (@8teAPi) January 3, 2024
1. Possible Meissner effect near room temperature in copper-substituted lead apatite
With copper-substituted lead apatite below room temperature, we observe diamagnetic dc magnetization under magnetic field of 25 Oe with remarkable bifurcation between zero-field-cooling and field-cooling measurements, and under 200 Oe it changes to be paramagnetism. A glassy memory effect is found during cooling. Typical hysteresis loops for superconductors are detected below 250 K, along with an asymmetry between forward and backward sweep of magnetic field. Our experiment suggests at room temperature the Meissner effect is possibly present in this material.
Hongyang Wang1, Yao Yao2†, Ke Shi3, Yijing Zhao3, Hao Wu4, Zhixing Wu5, Zhihui Geng6, Shufeng Ye1, and Ning Chen7
1 Center of Materials Science and Optoelectronics Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100049, China
2 State Key Laboratory of Luminescent Materials and Devices and Department of Physics, South China University of Technology, Guangzhou 510640, China
3 Beijing 2060 Technology Co., Ltd, Beijing 100084, China
4 School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
5 Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food safety, College of Chemistry, Fuzhou University, Fuzhou 350108, China
6 School of Engineering, Course of Applied Science, Tokai University, Hiratsuka 2591292, Japan
7 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
(Dated: January 3, 2024)
2. Researchers from Six Chinese Universities and research labs have found experimental proof of some superconductivity near room temperature for LK99 material.
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, China
Department of Physics, South China University of Technology, Guangzhou, China
Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, South China University of Technology, Guangzhou, China
School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, China
They observe a considerable hysteresis effect of low-field microwave absorption (LFMA) in copper-substituted lead apatite. By continuously rotating samples under external magnetic field, this effect is diminished which can not be renewed by a strong magnetic field but will be spontaneously recovered after two days, indicating its glassy features and excluding possibility of any ferromagnetism. The intensity of LFMA is found to sharply decrease at around 250K, suggesting a phase transition takes place. A lattice gauge model is then employed to assign these effects to the transition between superconducting Meissner phase and vortex glass, and the slow dynamics wherein is calculated as well.
3. Edge-sharing quasi-one-dimensional cuprate fragments in optimally substituted
Cu/Pb apatite
Katherine Inzani, School of Chemistry, University of Nottingham, United Kingdom
John Vinson, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899, USA
Sinead M. Griffin 3Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
The flurry of theoretical and experimental studies following the report of room-temperature superconductivity at ambient pressure in Cu-substituted lead apatite CuxPb10−x(PO4)6O (‘LK99’) have explored whether and how this system might host strongly correlated physics including superconductivity. While first-principles calculations at low doping (x ≈ 1) have indicated a Cu-d9 configuration coordinated with oxygen giving rise to isolated, correlated bands, its other structural, electronic, and magnetic properties diverge significantly from those of other known cuprate systems. Here we find that higher densities of ordered Cu substitutions can result in the formation of contiguous edge-sharing Cu-O chains, akin to those found in some members of the cuprate superconductor family. Interestingly, while such quasi-one-dimensional edge-sharing chains are typically ferromagnetically coupled along the chain, we find an antiferromagnetic ground-state magnetic order for our cuprate fragments which is in proximity to a ferromagnetic quantum critical point. This is a result of the elongated Cu-Cu distance in Cu-substituted apatite that leads to larger Cu-O-Cu angles supporting antiferromagnetism, which we demonstrate to be controllable by strain. Finally, our electronic structure calculations confirm the low-dimensional nature of the system and show that the bandwidth is driven by the Cu-O plaquette connectivity, resulting in an intermediate correlated regime.
4. The US Air Force Research Lab is funding Chapman University to study and try to replicate thin film LK99. DARPA may be following up with more extensive funding for thin film LK99.
A Lot of Rushed Nails in the Coffin of LK99
Nature had articles declaring LK99 science to be over.
On 14 August, a separate team at the Max Planck Institute for Solid State Research in Stuttgart, Germany, reported synthesizing pure, single crystals of LK-99. Unlike previous synthesis attempts, which had relied on crucibles, this one used a technique called floating-zone crystal growth. This enabled the researchers to avoid introducing sulfur into the reaction, thereby eliminating the Cu2S impurities.
The result was a transparent purple crystal — pure LK-99, or Pb8.8Cu1.2P6O25. Separated from impurities, LK-99 is not a superconductor, but an insulator with a resistance in the millions of ohms — too high for a standard conductivity test to be run. It shows minor ferromagnetism and diamagnetism, but not enough for even partial levitation. “We therefore rule out the presence of superconductivity,” the team concluded.
Paul Chu, the discoverer of the 90K SC YBCO, posted a paper last night putting the proverbial last nail on the LK99 coffin-“these anomalies are associated with… the impurity in their sample and not with superconductivity”
Paul Chu, the discoverer of the 90K SC YBCO, posted a paper last night putting the proverbial last nail on the LK99 coffin-“these anomalies are associated with… the impurity in their sample and not with superconductivity”Just disorder as we said before!https://t.co/3JgIkktZHr pic.twitter.com/SHLsevPTvE
— Condensed Matter Theory Center (@condensed_the) November 9, 2023
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
>>> Read full article>>>
Copyright for syndicated content belongs to the linked Source : Next Big Future – https://www.nextbigfuture.com/2024/01/lk99-superconductor-science-is-back-from-premature-burial-with-promising-experimental-results.html
