Hydrogen Pentagraphenelike Structure Stabilized by Hafnium: A High-Temperature Conventional Superconductor

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Recent discoveries of H3S and LaH10 superconductors have spurred the search for room-temperature superconductivity in superhydrides.
• High pressures are crucial for achieving high superconducting transition temperatures (Tc) in these materials.

Purpose of the Study:

• To introduce a new class of high-Tc hydrides with novel structures and properties.
• To predict the existence and properties of hexagonal HfH10.

Main Methods:

• First-principles calculations were employed to investigate the structural and electronic properties of HfH10 under high pressure.
• Phonon and electron-phonon coupling calculations were performed to predict the superconducting transition temperature (Tc).

Main Results:

• A novel hexagonal HfH10 structure was predicted to be stable at 250 GPa, exhibiting a remarkably high Tc of 213-234 K.
• The HfH10 structure features planar, pentagraphene-like hydrogen sublattices, distinct from previously known structures.
• Similar pentagraphene-like structures were predicted in ZrH10, ScH10, and LuH10, with high Tc values ranging from 134 to 220 K.

Conclusions:

• The discovery of HfH10 and related superhydrides with pentagraphene-like layered structures opens a new avenue for high-Tc superconductor research.
• These findings suggest that novel hydrogen-rich materials under pressure could host unprecedented superconducting properties.