Michel, C. and Baranovskii, S. D and Thomas, P. and Heimbrodt, W and Elm, M. T. and Klar, P. J. and Goldlücke, B. and Wurstbauer, Ursula and Reinwald, Matthias and Wegscheider, Werner
Quantitative modeling of the annealing-induced changes of the magnetotransport in Ga1−xMnxAs alloys.
Journal of Applied Physics 102 (7), 073712.
We study the changes of magnetoresistance induced by controlled thermal annealing at temperatures ranging from 300 to 600 °C of a Ga0.98Mn0.02As alloy grown by low-temperature molecular beam epitaxy. We use a resistor-network model for describing the electrical transport as a function of temperature and external magnetic field. The model is founded on classical semiconductor band transport and neglects many-body interactions. The peculiarities of dilute magnetic semiconductors, in particular, the magnetic-field induced changes of the density of states and the potential fluctuations due to the giant Zeeman splitting in the paramagnetic phase as well as spontaneous magnetization effects in the ferromagnetic phase, are accounted for in a mean-field fashion. This empirical transport model based on reasonable assumptions and realistic material parameters yields a satisfactory quantitative description of the experimentally obtained temperature and magnetic-field dependence of the resistivity of the entire series of annealed Ga0.98Mn0.02As samples, which exhibit metallic, semiconducting, and almost insulating transport behavior with increasing annealing temperature. Our analysis provides further understanding of the annealing-induced changes of the transport properties in dilute magnetic III-Mn-V semiconductors.
|Date:||11 October 2007|
|Institutions:|| Physics > Institute of Experimental and Applied Physics > Retired Professors > Group Werner Wegscheider|
|72.20.My; 72.80.Ey; 75.50.Pp; 75.20.Ck||PACS|
|Keywords:||annealing, electronic density of states, gallium arsenide, gallium compounds, III-V semiconductors, magnetoresistance, manganese compounds, paramagnetic materials, semimagnetic semiconductors, Zeeman effect|
|Subjects:||500 Science > 530 Physics|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||25 Jan 2010 13:51|
|Last Modified:||20 Jul 2011 22:18|