Formation of the single-phase ferromagnetic semiconductor (Ga,Mn)As by pulsed laser annealing

It is shown that (Ga,Mn)As layers formed by Mn⁺ ion implantation into GaAs and subsequent annealing by an excimer laser pulse with an energy density to 200–300 mJ/cm² feature the properties of the p-type semiconductor and ferromagnetic properties. The threshold dose of implanted ions (~10¹⁵ cm^–2) for activating Mn acceptors is determined. The sheet hole concentration and the Curie temperature increase with further increasing Mn⁺ ion dose. Hysteresis loops in the magnetic field dependences of the Hall effect, the negative magnetoresistance, and magnetic and structural studies suggest that the layers are analogues of single-phase ferromagnetic compounds (Ga,Mn)As formed by low-temperature molecular beam epitaxy.