Unexpected Room-Temperature Anomalous Hall Effect and Spin Hall Magnetoresistance in Cr0.08Co0.92Cl2/Pt Heterostructures

Abstract

Recent discovery of peelable van der Waals (vdW) magnets has opened new avenues for the advancement of atomic-level spintronic devices; however, their magnetic transition temperatures are typically well below room temperature. In spite of considerable explorations, including defect engineering, strain engineering, elemental doping, and the magnetic proximity effect (MPE), controllable fabrication of room-temperature vdW spintronic devices remains a great challenge. Herein, we report the growth of layered vdW Cr_0.08Co_0.92Cl₂ crystals, which exhibit antiferromagnetic ordering at approximately 23.4 K. Particularly, unexpected anomalous Hall effect (AHE) and spin Hall magnetoresistance (SMR) are observed in the 2D Cr_0.08Co_0.92Cl₂/Pt heterostructure at a much higher temperature of 300 K. These distinctive room-temperature magnetic signals are attributed to the MPE at the Cr_0.08Co_0.92Cl₂/Pt interface, which also result in a large spin Hall angle of 0.139. This study not only expands the transition metal dihalide family as 2D magnets, but also demonstrates room-temperature spintronic devices utilizing vdW magnets with otherwise low transition temperatures, paving a pathway for spintronic applications of 2D magnets.