Effect of Magnetic Impurities on Superconductivity in LaH <sub>10</sub>
Dmitrii V. Semenok, I. A. Troyan, A. V. Sadakov, Di Zhou, Michele Galasso, Alexander G. Kvashnin, Anna G. Ivanova, Ivan A. Kruglov, А. А. Быков, K. Yu. Terent’ev, A. V. Cherepakhin, O. A. Sobolevskiy, K. S. Pervakov, Alexey Yu. Seregin, Toni Helm, Tobias Förster, Audrey Grockowiak, S. W. Tozer, Yuki Nakamoto, Katsuya Shimizu, V. M. Pudalov, I. S. Lyubutin, Artem R. Oganov
Abstract
Abstract Polyhydrides are a novel class of superconducting materials with extremely high critical parameters, which is very promising for sensor applications. On the other hand, a complete experimental study of the best so far known superconductor, lanthanum superhydride LaH 10 , encounters a serious complication because of the large upper critical magnetic field H C2 (0), exceeding 120–160 T. It is found that partial replacement of La atoms by magnetic Nd atoms results in significant suppression of superconductivity in LaH 10 : each at% of Nd causes a decrease in T C by 10–11 K, helping to control the critical parameters of this compound. Strong pulsed magnetic fields up to 68 T are used to study the Hall effect, magnetoresistance, and the magnetic phase diagram of ternary metal polyhydrides for the first time. Surprisingly, (La,Nd)H 10 demonstrates completely linear H C2 ( T ) ∝ | T – T C |, which calls into question the applicability of the Werthamer–Helfand–Hohenberg model for polyhydrides. The suppression of superconductivity in LaH 10 by magnetic Nd atoms and the robustness of T C with respect to nonmagnetic impurities (e.g., Y, Al, C) under Anderson's theorem gives new experimental evidence of the isotropic (s‐wave) character of conventional electron–phonon pairing in lanthanum decahydride.