writer：LingYan Chen, XuYan Xue, HaiLiang Chen, BingYu Li, KaiPing Yang, WenCai Lu*
keywords：Superconductivity, Ternary hydrides, K-Y-H, High pressure, Genetic algorithm
source：期刊
specific source：Physics Letters A
Issue time：2021年
The search for high-Tcsuperconductors under high pressure has been a hot research topic. In this work, the structures under high pressure of ternary hydrogen-rich compounds KYHn(n =3-8, 10, 12 and 14) were searched by genetic algorithm method combined with the density function theory (DFT) method. The results showed that KYH8and KYH14demonstrate good stability and possess superconductivity. The KYH8-C2/mstructure has buckled “H3” units and heavy atom with layered arrangement. For the KYH14-Cmmmstructure, the rich H atoms form a cage-like structure with the K atom at the center. The electron-phonon coupling (EPC) calculations indicated that the Tc’s of KYH8-C2mare 111.3, 122.0 and 163.7 K at 200, 250 and 300 GPa, respectively. The KYH14-Cmmmwas predicted to have a Tcof 167.1 K at 300 GPa, and the strong EPC might be resulted mainly from the high-frequency vibrations of the H atoms.