Prediction of ternary superconducting YCH12 using a novel solid hydrogen source under high pressure

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 10; no. 46; pp. 17594 - 17601
• Main Authors: Ge Fei, Chen, Xin, Liu, Yunxian, Liu, Xiaobing
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.12.2022
• Subjects: Diamond anvil cells; High pressure; Hydrides; Hydrogen; Hydrogen permeation; Mechanical properties; Stoichiometry; Superconductivity; Superconductors
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d2tc04029h

Various hydrogen-rich superconductors have been theoretically predicted under high pressure, such as YH10 with the highest superconducting temperature Tc among the binary compounds. Following the theoretical discoveries, the subsequent experimental work has confirmed the high-Tc superconductivity in hydrogen-rich materials such as H3S and LaH10. However, most experiments use molecular hydrogen as the hydrogen source, which is difficult to seal due to the small H atoms. Besides, the possible hydrogen permeation may also affect the mechanical properties of a diamond anvil cell. Therefore, we examine ternary Y–C–H hydrides to search for a potential superconductor that can be possibly fabricated using a new solid hydrogen source adamantane (C10H16). Our ab initio calculations indicate that the YCH12 stoichiometry among various candidates is thermodynamically stable in the pressure range of 100–300 GPa. The triclinic YCH12 consisting of Y, Hn (n = 1, 3, 4, and 7) and CH4 motifs is a superconductor with an estimated Tc ∼ 112 K at 180 GPa. Its superconductivity derives from a large electron–phonon coupling (λ = 3.80), which depends on the contribution of Y atoms and evolution of ωlog under the pressure-induced chemical–structural transformations. These results will provide a novel route to explore promising high-Tc hydride superconductors.