Effect of Magnetic Impurities on Superconductivity in LaH10. Issue 42 (20th September 2022)

• Record Type: Journal Article
• Authors: Semenok, Dmitrii V.; Troyan, Ivan A.; Sadakov, Andrey V.; Zhou, Di; Galasso, Michele; Kvashnin, Alexander G.; Ivanova, Anna G.; Kruglov, Ivan A.; Bykov, Alexey A.; Terent'ev, Konstantin Y.; Cherepakhin, Alexander V.; Sobolevskiy, Oleg A.; Pervakov, Kirill S.; Seregin, Alexey Yu.; Helm, Toni; Förster, Tobias; Grockowiak, Audrey D.; Tozer, Stanley W.; Nakamoto, Yuki; Shimizu, Katsuya; Pudalov, Vladimir M.; Lyubutin, Igor S.; Oganov, Artem R.
• Is Part Of: Advanced materials. Volume 34:Issue 42(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-20
• Subjects: Anderson's theorem -- high pressure -- hydrides -- superconductivity; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202204038
• Languages: English
• ISSNs: 0935-9648

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 LaH10, 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 LaH10 : 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)H10 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 LaH10 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. Abstract : Anderson's theorem states that nonmagnetic impurities do not affect the isotropic order parameter in Bardeen–Cooper–Schrieffer (BCS) superconductors, whereas scattering on paramagnetic centers is very efficient in destroying the s‐wave superconductivity. This work demonstrates that LaH10, the best so far known superconductor, obeys Anderson's theorem, which makes it possible to adjust its critical temperature for a specific application.