Semimetallic "Electride Bands" Derived from Interlayer Electrons in Quasi-Two-Dimensional Electride Y${}_2$C

Abstract

Two-dimensional (2D) electrides are a new concept material in which anionic electrons are confined in the interlayer space between positively charged layers. We have performed angle-resolved photoemission spectroscopy measurements on Y${}_2$C, which is a possible 2D electride, in order to verify the formation of 2D electride states in Y${}_2$C. We clearly observe the existence of semimetallic "electride bands" near the Fermi level, as predicted by $ab$ $initio$ calculations, conclusively demonstrating that Y${}_2$C is a quasi-2D electride with electride bands derived from interlayer anionic electrons.

5 pages, 4 figures