Zero‐Dimensional Interstitial Electron‐Induced Spin–Orbit Coupling Dirac States in Sandwich Electride

Abstract

The development of inorganic electrides offers new possibilities for studying topological states due to the nonnuclear‐binding properties displayed by interstitial electrons. Herein, a sandwich electride 2[CaCl]+:2e− is designed, featuring a tetragonal lattice structure, including two atomic lattice layers and one interstitial electron layer. The interstitial electrons form nonsymmorphic‐symmetry‐protected Dirac points (DPs) at the X and M points, which are robust against the spin–orbit coupling effect. DPs exhibit an approximately elliptical shape, characterized by a relatively high anisotropy, resulting from the interplay between the electron and atomic layers. In addition, 2[CaCl]+:2e− possesses a lower work function (WF) (3.43 eV), endowing it with robust electron‐supplying characteristics. Due to the low WF and interstitial electrons, 2[CaCl]+:2e− loaded Ru shows outstanding catalytic performance for N2 cleavage. A potential research platform for exploring the formation of topological states and promoting nitrogen cracking in electrides is provided.

Keywords

• Dirac fermions
• low‐work function
• N2 cleavage
• 2D electrides