High-Temperature Superconductivity in a Th-H System under Pressure Conditions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• High-temperature superconductivity in hydrides is a rapidly developing field.
• Thorium, an element with s²d² electronic configuration, is explored for its potential to form superconducting polyhydrides.

Purpose of the Study:

• To predict new stable phases of thorium hydrides under high pressure.
• To investigate the superconducting properties of predicted thorium hydride phases.

Main Methods:

• Ab initio evolutionary algorithm (USPEX) for structure prediction.
• Density Functional Theory (DFT) for electronic structure calculations.
• Eliashberg formalism for superconductivity analysis.

Main Results:

• Prediction of a stable thorium decahydride (Fm3̅m-ThH₁₀) with a critical temperature (T_C) up to 241 K at 80-100 GPa.
• Identification of another superconducting phase, P2₁/c-ThH₇, with T_C of 62 K.
• Calculation of superconducting parameters including critical field (H_C) and energy gap (Δ₀).
• Prediction of other stable thorium hydrides: ThH₃, Th₃H₁₀, ThH₄, and ThH₆.

Conclusions:

• Thorium forms high-T_C superconducting polyhydrides, similar to other s²d¹ metals.
• The predicted ThH₁₀ phase represents a significant advancement in the search for high-temperature superconductors.
• Computational methods are effective in discovering novel superconducting materials.