Four Domestic Research Labs Say "LK-99 Is Not a Superconductor"

The Society of Superconductivity and Cryogenics to Release Briefing Materials on the Afternoon of the 31st

Four domestic research institutions failed to confirm superconductivity after producing and testing samples of the claimed room-temperature, ambient-pressure superconductor material (LK99).

[Image source=Yonhap News]

The Korean Society of Superconductivity and Cryogenics announced on the afternoon of the 31st that four domestic research institutions fabricated LK-99 according to the recipe provided by the Quantum Energy Research Institute and conducted reproduction experiments, but none showed superconducting properties.

Specifically, the High Pressure Research Institute at Hanyang University produced samples with compositions and characteristics similar to LK-99. Although there was a sudden change in resistance, they concluded that the electrical resistance was around 10^3 ohms (Ω)/cm, indicating the material was closer to an insulator rather than a conductor. The magnetic susceptibility also exhibited characteristics different from those of a superconductor.

The Complex Materials State Research Group at Seoul National University applied the method presented in the LK-99 paper published on arXiv by the Quantum Energy Research Institute on the 22nd of last month to produce samples. The resulting material had a somewhat different crystal structure. The resistivity increased by 5 to 10 times as the temperature decreased, and the magnetic susceptibility generally showed only weak diamagnetic properties.

The Quantum Materials Laboratory at Pusan National University reproduced two types of samples by slightly varying the composition ratios of the synthesized precursors. However, electrical resistance measurements showed semiconductor behavior with resistance increasing at low temperatures, and changes in resistance were observed between 150 and 180 Kelvin (K, approximately -120 to -93 degrees Celsius). They judged that this was not due to superconductivity-induced resistance reduction. This laboratory is currently analyzing the second synthesized sample.

The Physics Department research team at Pohang University of Science and Technology produced single crystals using a different process from the LK-99 paper, confirming insulating characteristics. This aligns with results announced in mid-month by the Max Planck Institute in Germany.

In addition to these four institutions, the Superconducting Materials and Applications Laboratory at Korea University, the Quantum Materials Superconductivity Research Group at Sungkyunkwan University, the Energy Materials Quantum Properties Laboratory at Kyung Hee University, and the Electronic Active Energy Materials Laboratory at Sungkyunkwan University are also conducting LK-99 sample fabrication and superconductivity verification experiments.

The society explained, "Even looking at foreign reproduction experiment results, the characteristics of fabricated samples vary significantly by research institution," adding, "It is helpful for drawing conclusions that multiple research institutions reproduce and measure as many samples as possible using various methods."

This content was produced with the assistance of AI translation services.