Prediction of Stoner-Type Magnetism in Low-Dimensional Electrides

TL;DR

This paper predicts stable low-dimensional magnetic electrides based on the Stoner mechanism, identifying specific compounds with significant spin-polarization energies and elucidating the role of interstitial electrons in magnetism.

Contribution

It introduces a new approach to identify stable magnetic electrides using the Stoner mechanism and predicts several compounds with high spin-polarization energies.

Findings

Identified stable magnetic electrides with spin-polarization energies up to 220 meV.

Demonstrated that interstitial electrons are the main source of magnetism.

Showed low-dimensionality enhances magnetic ground state formation.

Abstract

Electrides are special ionic solids with excess cavity-trapped electrons serving as anions. Despite the extensive studies on electrides, the interplay between electrides and magnetism is not well understood due to the lack of stable magnetic electrides, particularly the lack of inorganic magnetic electrides. Here, based on the mechanism of Stoner-type magnetic instability, we propose that in certain electrides the low-dimensionality can facilitate the formation of magnetic ground state because of the enhanced density of states near the Fermi level. To be specific, A5B3 (A = Ca, Sr, Ba; B = As, Sb, Bi) (1D), Sr11Mg2Si10 (0D), Ba7Al10 (0D) and Ba4Al5 (0D) have been identified as stable magnetic electrides with spin-polarization energies of tens to hundreds of meV per formula unit. Especially for Ba5As3, the spin-polarization energy can reach up to 220 meV. Furthermore, we demonstrate that the magnetic moment and spin density mainly derive from the interstitial anionic electrons near the Fermi level. Our work paves a way to the searching of stable magnetic electrides and further exploration of the magnetic properties and related applications in electrides.