The manganese effect on the magnetism and optical properties especially interband transitions of zinc sulphide

• Determination of the coupling nature between the two impurity manganese Jdd.
• Coupling nature between the valence and conduction band and d electrons of the Mn impurities.
• Obtaining the spin polarized optical gap for different concentration of manganese.
• Decrease in the optical gap for the spin up and the increase of the latter for the spin down.
• Identification of the peaks present in the dielectric function diagram.

The electronic, magnetic and optical properties of Mn doped zinc sulphide (ZnS:Mn) were calculated with the FP-LAPW method by using the LSDA and LSDA+U approximations. The latter one is shown to be necessary to account for the strong electron correlation in the Mn 3d shell. With the increase of Mn2+ concentration, the band gap is decreased for the spin-up channel and increased for the spin-down channel. Furthermore, to calculate the correct exchange couplings d–d and sp–d of Mn-doped ZnS, we have applied the Hubbard U parameter on Mn-d states. The influence of this Hubbard U parameter on the optical, electronic and magnetic properties of ZnS:Mn is investigated. We found that U=6 eV gives good results for exchange couplings and optical properties close to the experimental ones. The magnetic coupling between neighboring Mn impurities in ZnS is found to be antiferromagnetic.