A paper uploaded to the Arxiv preprint repository [arxiv.org] claims South Korean scientists have created the world's first room-temperature, ambient-pressure superconductor. The superconducting material, dubbed 'LK-99', is synthesized in a fairly simple manner from lead-apatite. As yet, there seems to be no independent verification of the claims of their paper.
See also:
https://thequantuminsider.com/2023/07/26/researchers-claim-they-developed-a-room-temperature-superconductor/ [thequantuminsider.com]
https://news.ycombinator.com/item?id=36864624 [ycombinator.com]