MXene heterostructures based on Cr2C and Cr2N: evidence of strong interfacial interactions that induce an antiferromagnetic alignment

Abstract

In the present work, Cr2C and Cr2N MXenes are stacked to conform 2D heterostructures. The structural, electronic, and magnetic properties were further investigated. Two stackings were treated; the first, Cr2C on top of Cr2N, and the second, Cr2N is on Cr2C. The most favorable configuration is Cr2C/Cr2N, with a vertical distance of 2.35 Å. The antiferromagnetic alignment evidences a possible bias exchange effect. Cr2C MXene preserves its ferromagnetic behavior and changes the top Cr layer polarization of Cr2N form the antiferromagnetic alignment with Cr2C. The bottom Cr layer of Cr2N conserves the intrinsic polarization as antiparallel. Electronic properties evidence a metallic behavior. Although the vertical distance in the MXene heterostructure is comparable with a van der Waals interaction, the 2D charge density maps and electron local function indicate a metallic interaction at the interface, meanwhile the charge density difference exhibits a charge transfer in the interface heterostructure. The new 2D heterostructure and the properties that emerge from it could be interesting to the spintronics community due to their applications in information storage devices.