Magnetic Isotropy/Anisotropy in Layered Metal Phosphorous Trichalcogenide MPS₃ (M = Mn, Fe)Single Crystals

Micromachines (Basel). 2018 Jun 11;9(6):292. doi: 10.3390/mi9060292.

Abstract

Despite the fact that two-dimensional layered magnetic materials hold immense potential applications in the field of spintronic devices, tunable magnetism is still a challenge due to the lack of controllable synthesis. Herein, high-quality single crystals MPS₃ (M= Mn, Fe) of millimeter size were synthesized through the chemical vapor transport method. After systemic structural characterizations, magnetic properties were studied on the bulk MPS₃ layers through experiments, along with first principle theoretical calculations. The susceptibilities as well as the EPR results evidently revealed unique isotropic and anisotropic behavior in MnPS₃ and FePS₃ crystals, respectively. It is worth noting that both of these materials show antiferromagnetic states at measured temperatures. The estimated antiferromagnetic transition temperature is 78 K for bulk MnPS₃ and 123 K for FePS₃ crystals. The spin polarized density functional theory calculations confirmed that the band gap of the antiferromagnetic states could be generated owing to asymmetric response all over the energy range. The ferromagnetic state in MnPS₃ and FePS₃ is less stable as compared to the antiferromagnetic state, resulting in antiferromagnetic behavior. Additionally, frequency-dependent dielectric functions for parallel and perpendicular electric field component vectors, along with the absorption properties of MPS₃, are thoroughly investigated.

Keywords: anisotropy; bulk single crystal; chemical vapor transport (CVT); density-functional theory (DFT); isotropy; layered material.