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.

Transition metal phosphorus trichalcogenides retain spin-charge coupling and lattice vibrations in different layers, which are useful for spintronic and optoelectronic devices. The phonon, magnons and excitonic properties of two-dimensional ternary nickel-phosphorus trisulfides (NiPS₃) are investigated using Raman spectroscopy and photoluminescence (PL) study. With magnetic exchange interaction, an exotic phonon scattering degenerates the optical phonons into in-plane A _g and B _g modes. We have observed eight Raman modes with two acoustic anisotropic magnon modes (M ¹, M ²) below the critical temperature for co-(XX), while only M ¹ at cross (XY) polarizations. The M ¹ mode is coupled with the phonon B _g mode that can survive after transition temperature. The phonon and magnon modes soften with variations in temperature, which is attributed to anharmonic phonon–phonon coupling and interlayer forces. The polarized Raman shows the two-fold and four-fold symmetry orientations of the phonon and magnon modes, respectively, which exhibit strong in-plane anisotropic phonon/magnon. The PL spectra revealed the existence of bound excitonic features and ensemble emitters in NiPS₃. The robust interlayer excitation and structural stability further revealed the optothermal properties. Moreover, the fabricated field-effect transistor on NiPS₃ reveals p-type semiconducting nature with an ON/OFF ratio of 5 × 10⁶ and mobility of ∼16.34 cm² V⁻¹ s⁻¹. In contrast, the rectification ratio indicates their diode characteristics. Similarly, the photocurrent is enhanced by changing the wavelength of light, which shows the potential for optoelectronics. The strong spin-charge interaction provides new insights into these materials’ magneto-optical and thermal properties for memory devices.