Direct observation of doping incorporation pathways in self-catalytic GaMnAs nanowires
Artikel i vetenskaplig tidskrift, 2015

Doping mechanisms of Mn in GaAs nanowires (NWs) that have been grown self-catalytically at 600 degrees C by molecular beam epitaxy (MBE) are investigated using advanced electron microscopy techniques and atom probe tomography, Mn is found to be incorporated primarily in the form of non-magnetic tetragonal Ga0.82Mn0.18 nanocrystals in Ga catalyst droplets at the ends of the NWs, while trace amounts of Mn (22 +/- 4 at. ppm) are also distributed randomly in the NW bodies without forming clusters or precipitates. The nanocrystals are likely to form after switching off the reaction in the MBE chamber, since they are partially embedded in neck regions of the NWs. The Ga0.82Mn0.18 nanocrystals and the low Mn concentration in the NW bodies are insufficient to induce a ferromagnetic phase transition, suggesting that it is difficult to have high Mn contents in GaAs even in 1-D NW growth via the vapor-liquid-solid process.


T. Kasama

Danmarks Tekniske Universitet (DTU)

Mattias Thuvander

Chalmers, Teknisk fysik, Materialens mikrostruktur

A. Siusys

Institute of Physics of the Polish Academy of Sciences

L. C. Gontard

CSIC-USE - Instituto de Ciencia de Materiales de Sevilla (ICMS)

A. Kovacs

Forschungszentrum Jülich

S. Yazdi

Danmarks Tekniske Universitet (DTU)

M. Duchamp

Forschungszentrum Jülich

A. Gustafsson

Lunds universitet

R. E. Dunin-Borkowski

Forschungszentrum Jülich

J. Sadowski

Institute of Physics of the Polish Academy of Sciences

Lunds universitet

Journal of Applied Physics

0021-8979 (ISSN) 1089-7550 (eISSN)

Vol. 118 054302

Enabling Science and Technology through European Electron Microscopy (ESTEEM 2)

Europeiska kommissionen (FP7), 2012-10-01 -- 2016-09-30.