Interlayer Coupling Induced Sharp Increase of the Curie Temperature in a Two-Dimensional MnSn Multilayer

Abstract

The MnSn monolayer synthesized recently is a novel two-dimensional ferromagnetic material with a hexagonal lattice, in which three Mn atoms come together to form a trimer, making it remarkably different from other magnetic two-dimensional materials. Most impressively, there occurs a sharp increase of the Curie temperature from 54 to 225 K when the number of layers increases from 1 to 3. However, no quantitative explanation has been reported in previous studies. Herein, by means of the first-principles calculation method and the Monte Carlo method, we demonstrate that strong interlayer ferromagnetic coupling plays an essential role in enhancing its critical temperature, which acts as a magnetic field to stabilize the ferromagnetism in MnSn multilayers. Our work not only explains the sharp increase of the Curie temperature of the MnSn film in experiments but also reveals that the interlayer coupling is a new routine to achieve high-temperature ferromagnetism in twodimensional materials.

Emergent Intrinsic Ferromagnetism in Two-Dimensional Trigonal Rhodium Oxide

“…Intuitively, with the number of layers decrease from bulk to few layers, the ferromagnetic order should be pronouncedly suppressed due to the quantum fluctuations and weakened interlayer ferromagnetic coupling . The experimentally observed ferromagnetism over a wide temperature range in SC-Tri-RhO 2 (see Figure S5 and Figure d) indicates that the long-range ferromagnetic order could survive even in the monolayer limit.…”

Prediction of transition metal carbonitride monolayers MN4C6 (M = Cr, Mn, Fe, and Co) made up of a benzene ring and a planar MN4 moiety

“…Based on the Heisenberg model and Monte Carlo method, the code had been developed by Zhang et al and has been successfully used in estimating the critical temperature of ferromagnetic monolayers. 34,43–45 For the ferromagnetic MnN 4 C 6 , FeN 4 C 6 , and CoN 4 C 6 monolayers, the couplings J m ( m = 1, 2, 3, and 4) are derived from the energy differences among FM, AFM-I, AFM-II, AFM-III, and Fi states and the values are listed in Table 4. Meanwhile, we estimate their Curie temperatures, and the magnetization and susceptibility variations with temperature are shown in Fig.…”