Mn diffusion in Ga1-xMnxAs/GaAs superlattices

In English Ga1-xMnxAs/GaAs superlattices with Mn concentrations of 1% and 5% in the Ga1-xMnxAs layers and a GaAs spacer thickness of 4 and 60 GaAs monolayers have been studied by cross-sectional scanning tunneling microscopy. By achieving atomic resolution of the superlattices, we observe individual Mn atoms in the Ga1-xMnxAs layers and in the GaAs spacer. We find that about 20% of the total amount of Mn diffuses from the GaMnAs layers into the GaAs spacer layers. Our results can be related to previous measurements of the magnetic properties of short period Ga1-xMnxAs/GaAs superlattices.