Recent reports of the superconductivity in hydrides of two different families(covalent lattice,as in SH3 and clathrate-type H-cages containing La and Y atoms,as in LaH10 and YH6)have revealed new families of high-Tc m...Recent reports of the superconductivity in hydrides of two different families(covalent lattice,as in SH3 and clathrate-type H-cages containing La and Y atoms,as in LaH10 and YH6)have revealed new families of high-Tc materials with Tc’s near room temperature values.These findings confirm earlier expectations that hydrides may have very high Tc’s due to the fact that light H atoms have very high vibrational frequencies,leading to high Tc values within the conventional Bardeen–Cooper–Schrieffer phonon mechanism of superconductivity.However,as is pointed out by Ashcroft,it is important to have the metallic hydrogen“alloyed”with the elements added to it.This concept of a metallic alloy containing a high concentration of metal-like hydrogen atoms has been instrumental in finding new high-Tc superhydrides.These new superhydride“roomtemperature”superconductors are stabilized only at very high pressures above 100 GPa,making the experimental search for their superconducting properties very difficult.We will review the current experimental and theoretical results for LaH10−x and YH6−x superhydrides.展开更多
基金V.S.acknowledges support fromthe Thousand Talent Program by the State Council of the People’s Republic of China.Portions of this work were performed at GeoSoilEnviroCARS(The University of Chicago,Sector 13)Advanced Photon Source(APS),Argonne National Laboratory.GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences(Grant No.EAR-1634415)Department of Energy-GeoSciences(Grant No.DE-FG02-94ER14466).This research used resources from the Advanced Photon Source,a U.S.Department of Energy(DOE)Office of the Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DEAC02-06CH11357.I.T.and A.G.acknowledge support from the Ministry of Science and Higher Education of the Russian Federation within the State assignment of the FSRC“Crystallography and Photonics”of RAS in part of the high-pressure structural experiments and from the Russian Science Foundation(Project No.19-12-00414)in part of the high-pressure studies of superconductivity.A.G.acknowledges the use of the facilities of the Center for Collective Use“AcceleratorCenter for NeutronResearch of the Structure of Substance and Nuclear Medicine”of the INR RAS.
文摘Recent reports of the superconductivity in hydrides of two different families(covalent lattice,as in SH3 and clathrate-type H-cages containing La and Y atoms,as in LaH10 and YH6)have revealed new families of high-Tc materials with Tc’s near room temperature values.These findings confirm earlier expectations that hydrides may have very high Tc’s due to the fact that light H atoms have very high vibrational frequencies,leading to high Tc values within the conventional Bardeen–Cooper–Schrieffer phonon mechanism of superconductivity.However,as is pointed out by Ashcroft,it is important to have the metallic hydrogen“alloyed”with the elements added to it.This concept of a metallic alloy containing a high concentration of metal-like hydrogen atoms has been instrumental in finding new high-Tc superhydrides.These new superhydride“roomtemperature”superconductors are stabilized only at very high pressures above 100 GPa,making the experimental search for their superconducting properties very difficult.We will review the current experimental and theoretical results for LaH10−x and YH6−x superhydrides.
