Recent Developments in Chemical Vapor Deposition of 2D Magnetic Transition Metal Chalcogenides

Abstract

In recent years, two-dimensional (2D) magnetic transition metal chalcogenides (TMCs) have attracted tremendous research interests thanks to their intriguing properties that are essential in developing future electronic and spintronic devices in this modernizing era. This review aims to introduce recent developments in the preparation of 2D magnetic TMCs, especially chromium and iron-based chalcogenides, their structures, as well as the related intriguing magnetic phenomena. First, the common crystal structures of magnetic TMCs including both layered and nonlayered structures are introduced. Various chemical vapor deposition strategies for synthesizing 2D magnetic TMCs are then introduced with emphasis on the key synthesis parameters. Moreover, the intriguing physical properties associated with 2D TMCs such as magnetic anisotropy, thickness, and phase-dependent magnetic response as well as stability are summarized. Last but not least, challenges and future research directions are briefly discussed in light of recent advances in the field.

Emerging Enhancement and Regulation Strategies for Ferromagnetic 2D Transition Metal Dichalcogenides

“…Magnetic anisotropy tends to be stronger in low‐dimensional materials or at surfaces and interfaces than in bulk materials and can be modulated by external electric fields, strain, etc. [ 15,18 ] Magnetic crystal anisotropy, plays an important role in magnetic recording and magnetic storage, and increasing the magnetic anisotropy performance can improve the stability and storage density of storage cells. Due to their strong anisotropy, stable spontaneous magnetization can exist in these monolayer 2D materials.…”

Magnetism of two-dimensional chromium tellurides

“… 16 , 52 , 53 , 54 , 55 , 56 , 57 However, the APCVD technique is predominantly utilized for its relatively simple setup and desired quality of final products in terms of great crystallinity, uniform composition, and ultrathin thickness. 20 , 58 , 59 , 60 The synthesis of ultrathin chromium tellurides, including van der Waals 1T-CrTe 2 and nonlayered Cr 2 Te 3 , Cr 3 Te 4 , Cr 5 Te 8 , and CrTe, using the CVD approach has been frequently reported in the past decade. For the preparation of 2D transition metal dichalcogenides (TMDCs), the strengths of the CVD approach mainly lay on the desirable quality of final products.…”

“… 19 Moreover, different stoichiometries and phases can be achieved by carefully tuning the synthesis parameters using the convenient ambient pressure chemical vapor deposition (APCVD) setup. 20 The thickness dependency 19 , 21 and strain dependency 22 , 23 , 24 , 25 of Cr x Te y provide fascinating controllability on 2D magnetism. Moreover, intriguing magnetic behaviors, such as skyrmions, 26 biskyrmions, 27 and anomalous Hall effect, 28 have also emphasized its important role as a model platform for fundamental research.…”

Ferromagnetism above room temperature in Janus Fe2X (X = S, Se) monolayers

“…and rich crystal structures because of the abundant oxidation states of TM elements. 5,16 In particular, TM-rich monolayers stabilized by quantum confinement effects are beneficial for the enhancement of local magnetic moment and magnetic coupling, which are the favorable factors for high-temperature ferromagnets. 17 Iron (Fe), as a representative magnetic TM element, also exhibits promising potential for 2D high-temperature magnetic materials, [18][19][20][21] especially for Fe-based chalcogenides.…”