Structural characterisation of spintronic GaMnAs and GaMnN heterostructures grown by molecular beam epitaxy

Observations of orthogonal orientations demonstrate the development of banded contrast features on inclined {-1-1-1}B planes for the [110] projection within micron thick samples, attributed to a compositional fluctuation in the Mn content. The relationship of Mn content and layer critical thickness...

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Bibliographic Details
Main Authors: Fay, Mike W., Han, Y., Novikov, Sergei V., Edmonds, K.W., Wang, K., Gallagher, B.L., Campion, R.P., Foxon, C.T., Brown, Paul D.
Other Authors: Cullis, A.G.
Format: Book Section
Published: Springer-Verlag 2005
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Online Access:https://eprints.nottingham.ac.uk/1469/
Description
Summary:Observations of orthogonal orientations demonstrate the development of banded contrast features on inclined {-1-1-1}B planes for the [110] projection within micron thick samples, attributed to a compositional fluctuation in the Mn content. The relationship of Mn content and layer critical thickness for the onset of precipitate and stacking fault formation is investigated. The formation of a Mn-O layer at the surface of the samples is also observed. The growth of GaMnN/(001)GaAs heterostructures with and without AlN/GaN buffer layers is also compared. Layers without buffer layers show MnAs inclusions into the GaAs, with a reduced Mn content of the GaMnN layer significantly below the nominal composition. The use of AlN/GaN buffer layers is found to greatly reduce the density of these MnAs inclusions, retaining a higher proportion of the Mn within the epilayer.