Examination of the magnetic exchange interactions in transition-metal thiophosphates*

2D magnetic semiconductors have become of late interest due to their magneto-optical effects in lowered dimensionality. More specifically, CrPS₄ has gained renewed attention due to its well-known features as an A-type AFM configuration prompting analysis and stability studies in its layered forms for use in scalable technology such as spintronic and optoelectronic devices. This study uses density functional theory (DFT) to report transition-metal thiophosphates (TMPS₄, TM = Cr, Mn, Fe) by taking the well-studied 2D van der Waals magnet CrPS₄ as a benchmark using experimentally determined values to confirm the parameters necessary to study TMPS₄ bulk compounds. Using model Hamiltonian calculations through exact diagonalization, we compare the DFT calculations and report on the magnetic and electronic ground state orders, Heisenberg exchange interactions, and phase diagrams between each TMPS₄ bulk compound.