https://techcrunch.com/2023/11/07/room-temperature-superconductor-false-claims/

After a raucous year of supposed breakthroughs in superconducting physics, 2023 is looking like it’s going to end with a whimper.

This summer, LK-99 was the room-temperature superconductor du jour. Its downfall was as swift as its rise; myriad experiments revealed that it was little more than a run-of-the-mill refrigerator magnet.