Tuning the Magnetism in Ultrathin CrxTey Films by Lattice Dimensionality

TL;DR

This study investigates how lattice dimensionality influences magnetism in ultrathin CrxTey films, revealing different magnetic states in monolayer and bilayer forms, with implications for 2D magnetic material design.

Contribution

It provides experimental and theoretical insights into the relationship between lattice structure and magnetic properties in ultrathin CrTe2 and Cr3Te4 films, highlighting the role of dimensionality.

Findings

Monolayer CrTe2 exhibits zigzag-antiferromagnetism.

Bilayer CrTe2 shows incipient ferromagnetism.

Bilayer Cr3Te4 demonstrates robust ferromagnetism with large perpendicular magnetic anisotropy.

Abstract

Two-dimensional (2D) magnetic transition metal compounds with atomic thickness exhibit intriguing physics in fundamental research and great potential for device applications. Understanding the correlations between their macrosopic magnetic properties and the dimensionality of microscopic magnetic exchange interactions are valuable for the designing and applications of 2D magnetic crystals. Here, using spin-polarized scanning tunneling microscopy, magnetization and magneto-transport measurements, we identify the zigzag-antiferromagnetism in monolayer CrTe2, incipient ferromagnetism in bilayer CrTe2, and robust ferromagnetism in bilayer Cr3Te4 films. Our density functional theory calculations unravel that the magnetic ordering in ultrathin CrTe2 is sensitive to the lattice parameters, while robust ferromagnetism with large perpendicular magnetic anisotropy in Cr3Te4 is stabilized through its anisotropic 3D magnetic exchange interactions.