For a relatively long time, the observation of the DC diamagnetic state in highly compressed nickelate superconductors [1],[2] has been a challenging experimental problem. And recently Li et al.[3] reported on the measurements of the DC diamagnetism in zero-field-cooled (ZFC) and field-cooled (FC) pressurized single crystal La2SmNi2O7. From the analysis of experimental data, Li et al.[3] reported that the superconducting phase fraction in their La2SmNi2O7 sample measured in the ZFC mode is 62.1%, and the superconducting phase fraction in the FC mode is 14.4%. It should be clarified that we regard the measurements of the DC diamagnetic state [3] in La2SmNi2O7 (and more recently in Pr4Ni3O10 [4]) as outstanding experimental results confirming bulk superconductivity in pressurized nickelates. However, we should note that Li et al.[3] made a threefold error in their calculations of the superconducting phase fraction in La2SmNi2O7. We believe that correcting this and other errors in Ref.[3] will benefit the physics community.
@article{arxiv.2602.23240,
title = {Threefold error in the reported zero-field cooled magnetic moment of single crystal $La_2SmNi_2O_7$},
author = {Aleksandr V. Korolev and Evgeny F. Talantsev},
journal= {arXiv preprint arXiv:2602.23240},
year = {2026}
}