Composition‐Dependent Magnetic Ordering in Freestanding 2D Non‐van der Waals Cr2TexSe3−x Crystals

Abstract

AbstractSince the confirmation of long‐range magnetic ordering in 2D materials, much effort has been devoted to finding more 2D magnetic materials with high Curie temperature (TC) and tunable physical properties. Most of the 2D magnets realized to date are based on van der Waals (vdW) materials, but recently synthesized 2D non‐vdW ultrathin materials have revealed an alternative direction for the discovery of novel 2D magnets. In this paper, a family of 2D non‐vdW Cr2TexSe3−x compounds is proposed. All Cr2TexSe3−x compounds are predicted to be energetically favorable and air stable, suggesting experimental feasibility, and long‐term stability. Compared to other non‐vdW materials, Cr2TexSe3−x compounds have superior oxidation resistance. Moreover, they exhibit obvious composition‐dependent magnetic ordering, which originates from the competition between interlayer direct antiferromagnetic exchange and ferromagnetic superexchange. Among them, half‐metals Cr2Te3 and Cr2TeSe2 exhibit robust ferromagnetism with high TC values of 396 and 261 K, respectively. Additionally, 2D Cr2TeSe2 shows a sizable anomalous Hall conductivity of 6237 Ω cm−1. The present results enrich the database of 2D non‐vdW magnets and provide fundamental understanding about the composition‐induced magnetic phase transition, which may be of use in spintronic applications.