Sr3CrN3: a new electride with partially filled d-shells

TL;DR

This paper reports the discovery and experimental validation of Sr3CrN3 as the first known electride with a partially filled d-shell, expanding the understanding and search criteria for new electride materials.

Contribution

It provides experimental evidence supporting the existence of electrides with partially filled d-shells, previously predicted by high-throughput computational screening.

Findings

Sr3CrN3 confirmed as an electride with partial d-shells

Experimental techniques validate theoretical predictions

Broadens criteria for electride material discovery

Abstract

Electrides are ionic crystals in which the electrons prefer to occupy free space, serving as anions. Because the electrons prefer to be in the pockets, channels, or layers to the atomic orbitals around the nuclei, it has been challenging to find electrides with partially filled d-shells, since an unoccupied d-shell provides an energetically favourable location for the electrons to occupy. We recently predicted the existence of electrides with partially filled d-shells using high-throughput computational screening. Here, we provide an experimental support using X-ray absorption spectroscopy and X-ray and neutron diffraction to show that Sr3CrN3 is indeed an electride despite its partial d-shell configuration. Our findings indicate that Sr3CrN3 is the first known electride with a partially filled d-shell, in agreement with theory, which significantly broadens the criteria for the search for new electride materials.