Superlattices of the form, Ga1–xMnxAs/GaAs, with Mn concentrations of 1 or 5% in the Ga1–xMnxAs layers and a GaAs spacer thickness of 4 and 60 GaAs monolayers were studied by cross-sectional scanning tunneling microscopy. By achieving atomic resolution of the superlattices, individual Mn atoms in the Ga1–xMnxAs layers and in the GaAs spacer were observed. It was found that about 20% of the total amount of Mn diffused from the GaMnAs layers into the GaAs spacer layers. These results could be related to previous measurements of the magnetic properties of short-period Ga1–xMnxAs/GaAs superlattices.

Mn Diffusion in Ga1–xMnxAs/GaAs Superlattices. A.Mikkelsen, L.Ouattara, H.Davidsson, E.Lundgren, J.Sadowski, O.Pacherova: Applied Physics Letters, 2004, 85[20], 4660-2