Superconductivity in Th–H and Pu–H Compounds under High-Pressure Conditions: A First-Principles Study

Hydrogen-rich materials synthesized at megabar pressures have revolutionized the field of high-temperature superconductivity. Among hydrogen-rich materials, clathrate hydrides which show near-room-temperature superconductivity have been discovered in recent years. Herein, clathrate actinide hydrides are constructed, and their electronic properties and electron–phonon interaction as well as superconductivity under high pressures are theoretically investigated with density functional theory tools. The calculations adopt projected-augmented-wave (PAW) approach. The Perdew–Burke–Ernzerhof (PBE)-type generalized gradient approximation (GGA) is used for the exchange–correlation potentials. Specifically, Th–H and Pu–H compounds are presented, of which the stability is demonstrated via calculated phonon dispersions, and the superconducting transition temperatures T_c under 100, 200, and 400 GPa are estimated. ThH₁₀ among Th–H compounds has the highest transition temperature of superconductivity, and T_c of ThH₁₀ can reach 151.8 K under 200 GPa. PuH₁₀ is also better than other investigated Pu–H compounds in superconductivity, but the highest T_c of PuH₁₀ is only 31.4 K under 400 GPa, much lower than that of ThH₁₀.