Short-Range Crystalline Order-Tuned Conductivity in Cr2Si2Te6 van der Waals Magnetic Crystals

ACS Nano. 2022 Aug 23;16(8):13134-13143. doi: 10.1021/acsnano.2c06080. Epub 2022 Aug 12.

Abstract

Two-dimensional magnetic materials (2DMMs) are significant not only for studies on the nature of 2D long-range magnetic order but also for future spintronic devices. Of particular interest are 2DMMs where spins can be manipulated by electrical conduction. Whereas Cr2Si2Te6 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 Cr2Si2Te6, on the length scale below 0.6 nm, induces a substantially reduced band gap and robust semiconducting behavior down to 2 K that turns to metallic above 10 GPa. Our results will be helpful in designing conducting states in 2DMMs and call for spin-resolved measurement of the electronic structure in exfoliated ultrathin crystals.

Keywords: Cr2Si2Te6; electronic structure; insulator−metal transition; short-range crystalline order; van der Waals ferromagnet.