Metallization and superconductivity in potassium-doped methane

Abstract

Metallization of methane (CH4) has always been an interesting issue. Here, we report a study on the structure, metallization and superconductivity in K-doped CH4 under pressure, based on the particle swarm optimization, density functional theory, and density functional perturbation theory. Summarizing the thermodynamical and dynamical stabilities, the electronic band structures, and the electron–phonon interaction calculations, we predicted that K-doped CH4 in [Formula: see text] space-group is a metal and a possible superconductor in the pressure range of [Formula: see text] GPa. The superconducting critical temperature is about 12.7 K at 80 GPa. It was found that the charge transfer from K to CH4 drives the metallization and mainly contributes to the electron–phonon interaction. The result confirms that CH4 can become a metal and superconductor under the electron doping and the relative low pressure.

Ternary superconducting cophosphorus hydrides stabilized via lithium

“…Earlier, through theoretical calculations, our group found that after the introduction of Mg in the insulating CH 4 system, the T c of MgCH 4 can reach 120 K at 121 GPa. 28 Recently, K was also doped into the CH 4 system in theoretical work 29 and T c was predicted to be 12.7 K at 80 GPa. In addtion, through adding Li into poor superconductive MgH 12 , Sun et al 30 found a high-T c superconductor Li 2 MgH 16 with T c about 473 K at 250 GPa.…”

Route to high- Tc superconductivity via CH4 -intercalated H3SCui1, Bi2, Shi3 et al. 2020Phys. Rev. B1406990View full textAdd to dashboardCite

“…CH 4 and Mg are predicted to form CH 4 Mg, a potential superconductor with a T c of 84-121 K at 75 to 120 GPa [31]. The related compound CH 4 K has a predicted T c of about 12 K at 80 GPa [32]. These results encouraged us to theoretically search for high-T c superconductors in the C-S-H ternary system.…”

Phonon-Mediated Low-Pressure Superconductivity in Ternary Hydride Ba–CH4

“…In this work, we therefore adopt CH 4 as the host material and explore the metallization at low pressures by combining the doping metal into the CH 4 crystal with pressure and then predict the possible high-temperature superconductivity. In previous studies, we have tried to use K, Be, and Li as charge-transfer sources and verified the feasibility of the study. − The Ba element has weaker electronegativity than Li, K, and Be which can enhance the charge transfer. At the same time, the Ba ion has a bigger radius which can improve the chemical pre-compression effect to accelerate the metallization at low pressures.…”