Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.11: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Influence of the structural transition from Ga_1−xMn_xAs alloys to granular GaAs:Mn/MnAs hybrids probed by magneto-transport — •M. Elm¹, J. Teubert¹, P.J. Klar¹, W. Heimbrodt¹, M. Reinwald², and W. Wegscheider² — ¹Dept. Physics and WZMW, Philipps-University of Marburg, Germany — ²Institute of Applied and Experimental Physics II, University of Regensburg, Germany

The magneto-resistance properties of Ga_0.98Mn_0.02As alloys on (311)A substrate grown by molecular beam epitaxy and corresponding GaAs:Mn/MnAs hybrid samples obtained by controlled thermal annealing at different temperatures were studied. Thermal annealing leads to the formation of MnAs clusters. The size of the clusters increases with increasing annealing temperature whereas the cluster density decreases accordingly. The magneto-resistance measurements were performed on Hall-bars with a length of 650 µm and a width of 200 µm in fields up to 10 T and in the temperature range from 2 to 280 K. Clear differences are observed in the transport behaviour of the alloy sample and the hybrid samples. The results are compared with measurements of GaMnAs/MnAs hybrid structures grown by MOVPE on (100) substrates.