中国物理B ›› 2025, Vol. 34 ›› Issue (8): 86201-086201.doi: 10.1088/1674-1056/add902
所属专题： SPECIAL TOPIC — Structures and properties of materials under high pressure
A novel metastable structure and superconductivity of hydrogen-rich compound CdH6 under pressure
Yan Yan(闫岩)1,†, Chengao Jiang(蒋成澳)1, Wen Gao(高稳)1, Rui Chen(陈蕊)1, Xiaodong Yang(杨晓东)1, Runru Liu(刘润茹)1, Lihua Yang(杨丽华)2, and Lili Wang(王丽丽)1
- 1 School of Materials Science and Engineering, Changchun University, Changchun 130022, China;
2 Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Key Laboratory of Preparation and Application of Environmental Friendly Materials, College of Physics, Jilin Normal University, Changchun 130103, China
A novel metastable structure and superconductivity of hydrogen-rich compound CdH6 under pressure
Yan Yan(闫岩)1,†, Chengao Jiang(蒋成澳)1, Wen Gao(高稳)1, Rui Chen(陈蕊)1, Xiaodong Yang(杨晓东)1, Runru Liu(刘润茹)1, Lihua Yang(杨丽华)2, and Lili Wang(王丽丽)1
- 1 School of Materials Science and Engineering, Changchun University, Changchun 130022, China;
2 Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Key Laboratory of Preparation and Application of Environmental Friendly Materials, College of Physics, Jilin Normal University, Changchun 130103, China
摘要： The particle swarm optimization algorithm has predicted a series of binary cadmium hydrides that could be dynamically stable at pressures between 100 GPa and 300 GPa. These low-energy phases are composed of both Cd atoms and H$_{2}$ molecules. Here, we propose a hitherto unknown metastable Cmcm-CdH$_{6}$ phase, consisting of one-dimensional zigzag graphite-like hydrogenic H$_{6}$ chains, quasimolecular H$_{2}$ units and Cd atoms, which is metallic above 290 GPa. Due to H$_{2} \sigma \to {\rm Cd}$ d donation and Cd $\rm d \to H_{2} \sigma^{\ast } $ back-donation, the electrons occupy antibonding orbitals for both types of hydrogen atoms. This results in weakened chemical bonds in the Cmcm-CdH$_{6}$ phase via a Kubas-like mechanism, promoting the emergence of high superconductivity, which is estimated to be up to $\sim 60 $ K at 290 GPa. This work will inspire the search for superconductivity in materials based on group IIB hydrides under pressure.
中图分类号: (High-pressure effects in solids and liquids)
- 62.50.-p