Three-dimensional ferromagnetism and magnetotransport in van der Waals Mn-intercalated tantalum disufide

TL;DR

This study investigates the magnetic, electronic, and transport properties of a 2D van der Waals ferromagnet, Mn-intercalated tantalum disulfide, revealing its 3D spin coupling, magnetic anisotropy, and magnetotransport behavior near its Curie temperature.

Contribution

It provides a comprehensive analysis of the magnetic interactions, electronic states, and magnetotransport phenomena in Mn$_{0.28}$TaS$_2$, a novel 2D ferromagnetic material with potential spintronics applications.

Findings

Mn$_{0.28}$TaS$_2$ exhibits a Curie temperature of ~82.3 K.

Spin coupling is of a 3D Heisenberg type with long-range interactions.

Anomalies in resistivity and thermopower near $T_c$ indicate strong carrier-moment interactions.

Abstract

Van der Waals (vdW) ferromagnets are an important class of materials for spintronics applications. The recent discovery of atomically vdW magnets CrI$_3$ and Cr$_2$Ge$_2$Te$_6$ has triggered a renaissance in the area of two-dimensional (2D) magnetism. Herein we systematically studied 2H-Mn$_{0.28}$TaS$_2$ single crystal, a 2D vdW ferromagnet with $T_c$ $\sim$ 82.3 K and a large in-plane magnetic anisotropy. Mn $K$-edge x-ray absorption spectroscopy was measured to provide information on its electronic state and local atomic environment. The detailed magnetic isotherms measured in the vicinity of $T_c$ indicates that the spin coupling inside 2H-Mn$_{0.28}$TaS$_2$ is of a three-dimensional (3D) Heisenberg-type coupled with the attractive long-range interaction between spins that decay as $J(r)\approx r^{-4.85}$. Both resistivity $\rho(T)$ and thermopower $S(T)$ exhibit anomalies near $T_c$, confirming that the hole-type transport carriers strongly interact with local moments. An unusual angle-dependent magnetoresistance is further observed, suggesting a possible field-induced novel magnetic structure.