Self-assembling of 1Sb4Mn magnetic clusters in GaAs:(Mn, Sb)

•Self-assembling of 1Sb4Mn magnetic clusters in GaAs:(Mn, Sb) is described.•The decrease of the enthalpy and strain energy is the cause of self-assembling.•1Sb4Mn cluster occurrence is a result of continuous phase transition.•The density of 1Sb4Mn clusters can be obtained in wide range.

The developed technology allowing to grow GaAs:Mn as substitutional alloys opens new perspectives for these materials and materials based on them. Self-assembling of 1Sb4Mn identical magnetic clusters in GaAs:(Mn, Sb) considered as MnxGa1−xSbyAs1−y substitutional alloys is represented. The self-assembling conditions with Mn and Sb contents in the dilute and ultra dilute limits, respectively, are obtained by the free energy minimization. The cluster occurrence temperatures do not depend on Sb content. The cluster occurrence and final stage of self-assembling when all Sb atoms are in clusters are results of continuous phase transitions. The portions of Mn atoms in clusters are 0.40, 0.53 and 0.80 at 255 °C, 191 °C and 88 °C, at Mn contents 2%, 3% and 4%, respectively, and at Sb content 0.4%.