Influence of background carriers on magnetic properties of Mn-doped dilute magnetic Si

► We calculated magnetic interactions in Mn doped dilute magnetic Si using hybrid exchange DFT. ► We find magnetic interactions depend on the type of back ground carriers. ► For 1.6% Mn, ground state is ferromagnetic for the p-type Si, but antiferromagnetic for the n-type. ► In p-type host, localisation of magnetic polarons on Mn enhances long range magnetic interaction. ► In n-type host e-e repulsion within Mn-Si impurity band destroys the long range spin polarisation.