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Unusual Spin Exchanges Mediated by the Molecular Anion P₂S₆^4-: Theoretical Analyses of the Magnetic Ground States, Magnetic Anisotropy and Spin Exchanges of MPS₃ (M = Mn, Fe, Co, Ni).

ABSTRACT: We examined the magnetic ground states, the preferred spin orientations and the spin exchanges of four layered phases MPS₃ (M = Mn, Fe, Co, Ni) by first principles density functional theory plus onsite repulsion (DFT + U) calculations. The magnetic ground states predicted for MPS₃ by DFT + U calculations using their optimized crystal structures are in agreement with experiment for M = Mn, Co and Ni, but not for FePS₃. DFT + U calculations including spin-orbit coupling correctly predict the observed spin orientations for FePS₃, CoPS₃ and NiPS₃, but not for MnPS₃. Further analyses suggest that the ||z spin direction observed for the Mn²⁺ ions of MnPS₃ is caused by the magnetic dipole-dipole interaction in its magnetic ground state. Noting that the spin exchanges are determined by the ligand p-orbital tails of magnetic orbitals, we formulated qualitative rules governing spin exchanges as the guidelines for discussing and estimating the spin exchanges of magnetic solids. Use of these rules allowed us to recognize several unusual exchanges of MPS₃, which are mediated by the symmetry-adapted group orbitals of P₂S₆^4- and exhibit unusual features unknown from other types of spin exchanges.

SUBMITTER: Koo HJ

PROVIDER: S-EPMC7961718 | biostudies-literature |

REPOSITORIES: biostudies-literature

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