Short-range Crystalline Order-Tuned Conductivity in Cr$_2$Si$_2$Te$_6$ van der Waals Magnetic Crystals

TL;DR

This study demonstrates that defect-induced short-range crystalline order in Cr$_2$Si$_2$Te$_6$ significantly reduces its band gap, enabling tunable conductivity from semiconducting to metallic under pressure, with implications for 2D magnetic device design.

Contribution

It reveals how short-range order in Cr$_2$Si$_2$Te$_6$ can tune electronic conductivity, a novel approach for manipulating 2D magnetic materials.

Findings

Short-range order reduces band gap and enables semiconducting behavior.

Applying pressure induces a transition from semiconducting to metallic state.

Defect engineering can control electronic properties in 2D magnetic crystals.

Abstract

Two-dimensional magnetic materials (2DMM) are significant for studies on the nature of 2D long range magnetic order but also for future spintronic devices. Of particular interest are 2DMM where spins can be manipulated by electrical conduction. Whereas Cr$_2$Si$_2$Te$_6$ exhibits magnetic order in few-layer crystals, its large band gap inhibits electronic conduction. Here we show that the defect-induced short-range crystal order in Cr$_2$Si$_2$Te$_6$ on the length scale below 0.6 nm induces substantially reduced band gap and robust semiconducting behavior down to 2 K that turns to metallic above 10 GPa. Our results will be helpful to design conducting state in 2DMM and call for spin-resolved measurement of the electronic structure in exfoliated ultrathin crystals.