LK-99 is a potentially groundbreaking material that has been touted as a room-temperature superconductor, boasting a gray-black appearance and a hexagonal structure that diverges slightly from that of lead-apatite, due to the introduction of small amounts of copper. The substance was first synthesized and investigated by a team of researchers including Sukbae Lee and Ji-Hoon Kim from Korea University.
The research team contends that LK-99 displays superconductivity at ambient pressure and below 400 K (127 °C; 260 °F), which, if verified, would mark a significant breakthrough in the realm of material science. However, it is crucial to note that as of July 31, 2023, no independent verification of LK-99's superconducting properties at any temperature has been confirmed.
The original discovery and subsequent claims about LK-99's potential superconductivity have yet to undergo rigorous peer review and independent replication, casting a shroud of uncertainty over the initial findings. The scientific community at large has responded primarily with skepticism, largely owing to the extraordinary nature of the researchers' claims and the apparent errors and inconsistencies found in the pre-published papers. Despite this, independent teams are currently endeavoring to replicate the South Korean team's work, spurred on by the straightforward method of producing the material. Initial results from these efforts are expected in August 2023.
The initial studies heralding the discovery of LK-99 were uploaded to arXiv, a repository of electronic preprints (known as e-prints) approved for posting after moderation. There are indications that these preprint papers may not represent the full scope of the research, as Lee claimed that the uploaded documents were incomplete. Moreover, coauthor Hyun-Tak Kim acknowledged that one of the papers contained defects. As the scientific world awaits further developments, the case of LK-99 underscores the importance of thorough review and independent verification in scientific discovery.