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arXiv · 1401.6791

Determination of the Fermi Level Position in Dilute Magnetic Ga$_{1-x}$Mn$_{x}$N Films

Stefan Barthel·Gerd Kunert·Mariuca Gartner·Mihai Stoica·Daniel Mourad·Carsten Kruse·Stephan Figge·Detlef Hommel·Gerd Czycholl
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Abstract

We report on a combined theoretical and experimental determination of the Fermi level position in wurtzite Ga$_{1-x}$Mn$_{x}$N films with $x=4\%$ and $x=10\%$ as grown by molecular beam epitaxy. By means of ellipsometric measurements the real part of the frequency-dependent conductivity is determined. An electronic model in the framework of the effective bond-orbital model is parameterized in order to theoretically reproduce the measured transport properties. Predictions for the long-wavelength behaviour as a function of the Fermi level are made. The corresponding density of states obtained in this model is in qualitative agreement with first-principle calculations. The absence of a significant experimental peak in the AC conductivity for small frequencies indicates that the Fermi level lies in a gap between two Mn-related impurity bands in the host band gap.

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Stefan Barthel, Gerd Kunert, Mariuca Gartner, Mihai Stoica, Daniel Mourad, Carsten Kruse, Stephan Figge, Detlef Hommel, Gerd Czycholl. 2014-03-12. Determination of the Fermi Level Position in Dilute Magnetic Ga$_{1-x}$Mn$_{x}$N Films. https://doi.org/10.1063/1.4869134

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