Article
Analysis of the zero-field cooled magnetic moment of a highly compressed La2SmNi2O7 single crystal
A. V. Korolev
M.N. Mikheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences, S. Kovalevskaya St., 18, 620108, Ekaterinburg, Russia
E. F. Talantsev
M.N. Mikheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences, S. Kovalevskaya St., 18, 620108, Ekaterinburg, Russia
e-mail: evgeny.talantsev@imp.uran.ru
DOI: https://doi.org/10.62539/2949-5644-2026-4-1-90-101
Abstract
For a relatively long time, the observation of the DC diamagnetic state in highly compressed nickelate superconductors has been a challenging experimental problem. And only recently several research groups reported results of measurements of the DC diamagnetism in zero-field-cooled (ZFC) and field-cooled (FC) pressurized single crystals Ruddlesden-Popper nickelates. One research group reported that the superconducting phase fraction in the La2SmNi2O7 samples 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 in La2SmNi2O7 as outstanding experimental results confirming bulk superconductivity in pressurized Ruddlesden-Popper nickelates. However, our analysis of the raw experimental data reported for the ZFC experiment on the La2SmNi2O7 samples based on the standard methodology showed that there is a significant overestimation of the content of the superconducting phase fraction in several pressurized Ruddlesden-Popper nickelate samples. We believe that highlighting the aforementioned problems to a broad community of physicists will benefit the community.
Keywords: Superconductivity in materials under extreme conditions; Ruddlesden-Popper nickelate superconductors; Meissner effect; Diamagnetic moment of superconductors.
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