Superconducting TaH5 at high pressure

Abstract

Recently, the significant development, in the field of high-temperature superconductivity among the compressed elements hydrides (such as LaH _10 ), opens up a door in pursuing room-temperature superconductors. Therefore, the investigations of excellent superconductivity in hydrogen-rich materials have become a hot topic of considerable interest. Herein, we explore the stabilities of compressed tantalum polyhydrides TaH _n ( n = 1–6) and the superconductivity by using a particle swarm optimization structure prediction methodology in combination with the first-principles electronic structure framework. As a result of structure searches, we identified a stable TaH _5 compound under high pressure, which consists edge shared TaH _12 polyhedra. Remarkably, within Allen–Dynes modified McMillan equation, our predicted TaH _5 is a superconductor with superconducting critical temperature ( T _c ) of 18–23 K at 100 GPa.

Keywords

• superconductor
• polyhydride
• high pressure
• first-principles