Predicted novel insulating electride compound between alkali metals lithium and sodium under high pressure

Abstract

The application of high pressure can fundamentally modify the crystalline and electronic structures of elements as well as their chemical reactivity, which could lead to the formation of novel materials. Here, we explore the reactivity of lithium with sodium under high pressure, using a swarm structure searching techniques combined with first-principles calculations, which identify a thermodynamically stable LiNa compound adopting an orthorhombic oP8 phase at pressure above 355 GPa. The formation of LiNa may be a consequence of strong concentration of electrons transfer from the lithium and the sodium atoms into the interstitial sites, which also leads to opening a relatively wide band gap for LiNa-op8. This is substantially different from the picture that share or exchange electrons in common compounds and alloys. In addition, lattice-dynamic calculations indicate that LiNa-op8 remains dynamically stable when pressure decompresses down to 70 GPa.

14 pages, 6 figures

References in corpus (4)

• Quasiparticle band structure based on a generalized Kohn-Sham scheme
• Tetrahedral clustering in molten lithium under pressure
• High pressure superconducting phase diagram of 6Li: anomalous isotope effects in dense lithium
• Electronic and structural ground state of heavy alkali metals at high pressure

Cited by in corpus (4)

• Interplay of anionic quasi-atom and interstitial point defects in electrides: abnormal interstice occupation and colossal charge state of point defects in dense FCC-lithium
• Simultaneous Superconducting and Topological Properties in Mg-Li Electrides at High Pressures
• Prediction of Stable Ground-State Binary Sodium-Potassium Interalkalis under High Pressures
• Universal Metallic Surface States in Electride