Unexpected Magnetism in Alkaline Earth Mono-Silicides

TL;DR

This study reveals unexpected magnetic properties in alkaline earth mono-silicides, showing that their unique electronic structure and atomic arrangement lead to magnetic instabilities and glassy behavior, challenging previous assumptions about their metallic nature.

Contribution

The paper uncovers the magnetic instabilities in alkaline earth mono-silicides and links their electronic structure and atomic arrangement to their magnetic properties, which was not previously understood.

Findings

Presence of magnetic instabilities in alkaline earth mono-silicides

Weak glassy magnetic behavior observed

Electronic structure involves depopulated Si π-system and metal d-states

Abstract

Alkaline earth mono-silicides ({\AE}Si, {\AE} $=$ Ca, Sr, Ba) are poor metals and their transport properties are not solely determined by the Zintl anion, in contrast to their Zintl-type composition. Their conducting network is formed by the depopulated ${}^{1}_{\infty}$[Si$^{2-}$] $\pi$-system and {\AE}-$d$ states. This justifies the special local coordination of the metal atoms and the planarity of the silicon chains. The low density of carriers seems to be a playground for magnetic instabilities and the triangular prismatic arrangement of {\AE} atoms responsible for the observed weak glassy behavior.