Magnetic avalanche of non-oxide conductive domain walls

TL;DR

This paper reports the discovery of conductive ferroelectric domain walls in a non-oxide material, GaV4S8, where magnetic control induces giant conductance changes, revealing new physics beyond oxide-based systems.

Contribution

It introduces a new mechanism for conductive domain walls in non-oxide ferroelectrics driven by multivalent molecular clusters, enabling magnetic control of conductance.

Findings

Conductive domain walls in GaV4S8 exhibit nanoscale stripe structures.

Magnetic control induces giant conductance changes up to eight orders of magnitude.

Non-oxide ferroelectrics can host novel hybrid domain wall phenomena.

Abstract

Atomically sharp domain walls (DWs) in ferroelectrics are considered as an ideal platform to realize easy-to-reconfigure nanoelectronic building blocks, created, manipulated and erased by external fields. However, conductive DWs have been exclusively observed in oxides, where DW mobility and conductivity is largely influenced by stoichiometry and defects. In contrast, we here report on conductive DWs in the non-oxide ferroelectric GaV$_4$S$_8$, where charge carriers are provided intrinsically by multivalent V$_4$ molecular clusters. We show that this new mechanism gives rise to DWs composed of nanoscale stripes with alternating electron and hole conduction, unimaginable in oxides. By exerting magnetic control on these segments we promote the mobile and effectively 2D DWs into dominating the 3D conductance, triggering abrupt conductance changes as large as eight orders of magnitude. The flexible valency, as origin of these novel hybrid DWs with giant conductivity, demonstrates that non-oxide ferroelectrics can be the source of novel phenomena beyond the realm of oxide electronics.