Work

One‐Dimensional Hydrogen Chains in Li–Hf–H System: A Pathway to High Superconductivity Under High Pressure

Year: 2025

Type: article

Abstract: The recent discovery of high‐critical‐temperature (high‐ T c ) superconductivity in hydrides such as H 3 S and LaH 10 has significantly advanced the quest for room‐temperature superconductors. This work reports a new class of high‐ T c hydrides in the Li–Hf–H system characterized by unknown one‐dimensional (1D) hydrogen chains. Through structure prediction methods and first‐principles calculations, the thermodynamically stable compound LiHfH 20 is discovered, exhibiting a remarkable T c of 222 K at 260 GPa. Notably, the distinct 1D hydrogen chains in LiHfH 20 facilitate strong coupling between high‐frequency phonon modes and hydrogen‐derived electronic states near the Fermi level, significantly enhancing superconductivity. Extending this concept to other MX H 20 compounds ( M and X represent the other 27 elements), it is demonstrated that hole doping further increases the T c , exemplified by isostructural BeCaH 20 , which achieves a T c of 262 K. These findings provide novel and viable high‐pressure hydrides with 1D hydrogen chain for future experimental synthesis toward room‐temperature superconductivity.

Source: Advanced Science

DOI: 10.1002/advs.202514126