First-principles Investigation of Electrides Derived from Sodalites

TL;DR

This study proposes a new method to create thermally stable electrides from sodalite structures by removing anionic sites, revealing promising applications in catalysis, optics, and spintronics.

Contribution

The paper introduces a novel approach to synthesize stable electrides from sodalites through anionic site removal, expanding potential applications.

Findings

Electrides with localized electrons near the Fermi level were successfully simulated.

The materials are expected to be more thermally stable than previous electrides.

Na$_4$(AlSiO$_4$)$_3$ exhibits magnetic properties due to localized excess electrons.

Abstract

Recently, the electride materials, with excess anionic electrons confined in their empty space, have received a growing attention due to their promising applications in catalysis, nonlinear optics and spin-electronics. However, the utilization of electride materials is limited by their thermal instability. Here we introduce an alternative way to achieve the localized anionic electron states via the removal of high symmetric Wyckoff sites of anions from the existing sodalite compounds. Using four halide sodalites as the parental structures, our simulation reveals that the materials after the removal of anionic halide sites exhibit typical electride behaviors that are characterized by the existence of localized electronic states near the Fermi level. Compared to most previously studied electrides, these materials are expected to be more thermally stable due to the complex structural framework and thus promising for practical applications. Among them, Na$_4$(AlSiO$_4$)$_3$ manifests magnetic electronic structure. We demonstrate that this magnetism originates from a highly localized excess electron state surrounded by electronpositive alkaline cations. Our results suggest Na$_4$(AlSiO$_4$)$_3$ could be a promising spintronics component, thus encouraging further experimental study.