Curie temperature and carrier concentration gradients in epitaxy-grown Ga1−xMnxAs layers
| Autor: | H. Bracht, K. Thonke, S. Frank, Paul J. Ziemann, Wladimir Schoch, Andreas Waag, V. Avrutin, Michael Krieger, Wolfgang Limmer, S. Brotzmann, A. Koeder, Rolf Sauer, K. Zuern |
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| Rok vydání: | 2003 |
| Předmět: |
Diffraction
Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Epitaxy Electrochemistry Condensed Matter::Materials Science symbols.namesake Ferromagnetism Homogeneous symbols Curie temperature Concentration gradient Raman spectroscopy |
| Zdroj: | Applied Physics Letters. 82:3278-3280 |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/1.1573369 |
| Popis: | We report on detailed investigations of the electronic and magnetic properties of ferromagnetic GaMnAs layers, which have been fabricated by low-temperature molecular-beam epitaxy. Superconducting quantum interference device measurements reveal a decrease of the Curie temperature from the surface to the GaMnAs/GaAs interface. While high resolution x-ray diffraction clearly shows a homogeneous Mn distribution, a pronounced decrease of the carrier concentration from the surface towards the GaMnAs/GaAs interface has been found by Raman spectroscopy as well as electrochemical capacitance-voltage profiling. The gradient in Curie temperature seems to be a general feature of GaMnAs layers grown at low-temperature. Possible explanations are discussed. |
| Databáze: | OpenAIRE |
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