Ga1−xMnxAs/(001) GaAs (x = 2.2, 5.6, 9at%) epitaxial layers grown by low-temperature molecular beam epitaxy, exhibiting anisotropic magnetic properties, were characterized using a range of transmission electron microscopy techniques and secondary-ion mass spectrometry. Banded contrast features on inclined planes were observed for the [110] projection of micron-thick samples with high Mn content, and were attributed to a compositional fluctuation in the interstitial Mn content. Precipitates attributed to tetragonally distorted MnAs were associated with the onset of stacking-fault formation during layer growth. The formation of an Mn–O layer at the surface of the samples was also observed, attributed to post-growth oxidation of an Mn surfactant layer.

Characterization of Ga1-xMnxAs/(001)GaAs Epilayers Grown by Low-Temperature Molecular Beam Epitaxy. M.W.Fay, Y.Han, P.D.Brown, K.W.Edmonds, K.Wang, B.L.Gallagher, R.P.Campion, C.T.Foxon: Philosophical Magazine Letters, 2006, 86[6], 395-401