Zhou et al., in their recent publication (Nat. Commun. 16, 1135, 2025), reported the synthesis of lanthanum superhydride, LaHx (x = 10.2-11.1), by laser heating LaH3 with NH3BH3 at a pressure of 170 GPa and investigated the temporal evolution of the NMR spectra of the reaction products. They observed a gradual decrease in the 1H-NMR signal intensity assigned to the synthesized metal hydride, accompanied by an increase in molecular hydrogen within the sample chamber over a period of 50 days. Based on these observations, the authors concluded that LaH10 progressively decomposes into LaH3 and H2 within two months after synthesis at its formation pressure of 170 GPa. Here, we demonstrate that, under their formation conditions, metal superhydrides are thermodynamically more stable than metal trihydrides. Furthermore, we present direct experimental evidence - based on X-ray diffraction and four-probe electrical resistance measurements - confirming the stability of both the crystal lattice and high-temperature superconducting properties of the Fm-3m-LaH10 phase for more than five years. This long-term stability is consistent with predictions from quantum chemistry calculations.
@article{arxiv.2507.08009,
title = {Long-Term Stability of Superconducting Metal Superhydrides},
author = {Vasily S. Minkov and Mikhail A. Kuzovnikov and Panpan Kong and Alexander P. Drozdov and Feng Du and Jiafeng Yan and Jaeyong Kim and Stella Chariton and Vitali B. Prakapenka and Mohamed Mezouar and Björn Wehinger and G. Alexander Smith and Fedor F. Balakirev and Evgeny F. Talantsev},
journal= {arXiv preprint arXiv:2507.08009},
year = {2025}
}
Comments
7 Pages, 3 Figures. Comment on arXiv:2408.13419 / doi: 10.1038/s41467-025-56033-3