Effect of the Local Environment on the Magnetic Properties of Mn3Si: Hybrid Ab Initio and Model Study

The effect of the local environment on the formation of magnetic moments on Mn atoms in manganese silicide Mn3Si is studied by the combination of ab initio calculations and the model analysis. The suggested approach is related to the self-consistent mapping of the results of ab initio calculations to a multiorbital model. The model analysis allows to reveal the role played by the local environment of the transition metal atoms on the magnetic moments formation. It is found that the formation of the magnetic moment is controlled rather by hopping parameters between Mn atoms, not by the number of Mn-Si nearest neighbors. Particularly, the formation of magnetic moment on MnI atom is mainly controlled by the hopping parameter between nearest Mn atoms, while the magnetic moment on MnII atom is primarily determined by the hoppings between next-nearest Mn atoms. The obtained phase diagrams of the magnetic state show the presence of a sharp boundary with respect to the hopping between Mn atoms. This opens the opportunity to turn on or turn off the magnetic state by the external impacts. The ab initio calculations of Mn3Si well agree with the results of model consideration and confirm the model conclusions.