Theoretical study of small clusters of manganese - doped gallium oxide : Mn ( GaO ) n and Mn 2 ( GaO ) n with n 5 1 2 7

Structures, electronic and magnetic properties of Mn and Mn2 doped stoichiometric (GaO)n clusters with n = 1-7 are studied in the framework of density functional theory. Doping of a Mn atom is found to be energetically favorable in (GaO)n clusters and the equilibrium configurations are found to be determined by the metal–oxygen interactions. Mn prefers to maximize the number of Mn–O bonds by selecting a Ga site in the cluster which increases its coordination with oxygen. Addition of a Mn atom in Mn(GaO)n clusters results into the ground state to be either ferromagnetic or antiferromagnetic depending on the Mn coordination number and the Mn–Mn bond-length in the given Mn2(GaO)n cluster.