Ternary superhydrides under pressure of Anderson's theorem: Near-record superconductivity in (La,Sc)H${}_{12}$

Abstract

Lanthanum-hydrogen system and its derivatives remain among the most promising for achieving room-temperature superconductivity. In this study, we examined the formation of ternary lanthanum-scandium superhydrides at pressures up to 220 GPa. The primary product of the LaSc alloy's reaction with hydrogen is newly discovered cubic (La,Sc)H${}_{12}$, demonstrating clear superconducting transition in all six channels of the van der Pauw scheme below 244-248 K. In this compound with an unusually large unit cell volume, virtually no magnetoresistance was observed in fields up to 68 Tesla. Synthesized samples of (La,Sc)H${}_{12}$ demonstrate pronounced superconducting diode and SQUID-like effects at a record high temperature of 233 K. Furthermore, our analysis revealed the formation of lower hexagonal polyhydrides (La,Sc)H${}_{6-7}$, which could potentially account for the anomaly in electrical resistance observed near 274 K. This anomaly between 265-290 K also appears in the radio-frequency transmission measurements and may be of a superconducting nature.

In the new version we have added radio-frequency measurements (Figure 5), as well as a number of additional figures in the Supp. Info

References in corpus (22)

• High-pressure phases of silane
• Superconductivity at 253 K in lanthanum-yttrium ternary hydrides
• Enhancement of the superconducting critical temperature realized in the La-Ce-H system at moderate pressures
• Efficient route to achieve superconductivity improvement via substitutional La-Ce alloy superhydride at high pressure
• Superconducting Phase-Diagram of H3S under High Magnetic Fields
• High-temperature superconductivity on the verge of a structural instability in lanthanum superhydride
• Nonstandard superconductivity or no superconductivity in hydrides under high pressure
• Effect of paramagnetic impurities on superconductivity in polyhydrides: $\text{s}$-wave order parameter in Nd-doped LaH${}_{10}$
• High-temperature superconductivity in hydrides
• High-Pressure Synthesis of Seven Lanthanum Hydrides with a Significant Variability of Hydrogen Content
• Non-Fermi-Liquid Behavior of Superconducting SnH${}_4$
• Large negative magnetoresistance and pseudogap phase in superconducting A15-type La${}_4$H${}_{23}$
• Sr-Doped Molecular Hydrogen: Synthesis and Properties of SrH${}_{22}$
• Quantum anharmonic enhancement of superconductivity in $P{6}_3/mmc$ ScH${}_6$ at high pressures: a first-principles study
• Prediction of Room-Temperature Superconductivity in Quasi-atomic H2-Type Hydrides at High Pressure
• Vortex phase dynamics in yttrium superhydride YH${}_6$ at megabar pressures
• Universal Fermi velocity in highly compressed hydride superconductors
• A-15 type superconducting hydride $L{a}_4{H}_{23}$: Nanograined structure with low strain, strong electron-phonon interaction, and moderate level of nonadiabaticity
• Raisins in a Hydrogen Pie: Ultrastable Cesium and Rubidium Polyhydrides
• Quasi Two-dimensional Vortex Matter in ThH${}_{10}$ Superhydride
• Superconducting memory and trapped magnetic flux in ternary lanthanum polyhydrides
• Observation of the Josephson effect in superhydrides: DC SQUID based on (La,Ce)H${}_{10+x}$ with operating temperature of 179 K

Cited by in corpus (2)

• Stability and Superconductivity of Ternary Polyhydrides
• Transmission of radio-frequency waves and nuclear magnetic resonance in lanthanum superhydrides