Local structure of (Ga,Fe)N and (Ga,Fe)N:Si investigated by x-ray absorption fine structure spectroscopy
- 28 May 2009
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 79 (19), 195209
- https://doi.org/10.1103/physrevb.79.195209
Abstract
X-ray absorption fine-structure (XAFS) measurements supported by ab initio computations within the density functional theory (DFT) are employed to systematically characterize Fe-doped as well as Fe- and Si-codoped films grown by metalorganic vapor-phase epitaxy. The analysis of extended-XAFS data shows that depending on the growth conditions, Fe atoms either occupy Ga substitutional sites in GaN or precipitate in the form of nanocrystals, which are ferromagnetic and metallic according to the DFT results. Precipitation can be hampered by reducing the Fe content, by increasing the growth rate, or by codoping with Si. The near-edge region of the XAFS spectra provides information on the Fe charge state and shows its partial reduction from to upon Si codoping, in agreement with the Fe electronic configurations expected within various implementations of DFT.
Keywords
Other Versions
This publication has 48 references indexed in Scilit:
- Controlled Aggregation of Magnetic Ions in a Semiconductor: An Experimental DemonstrationPhysical Review Letters, 2008
- Local electronic structure of Cr in the II–VI diluted ferromagnetic semiconductor Zn1-xCrxTeNew Journal of Physics, 2008
- Observation of Strong-Coupling Effects in a Diluted Magnetic SemiconductorPhysical Review Letters, 2008
- Ferromagnetic nitride-based semiconductors doped with transition metals and rare earthsSemiconductor Science and Technology, 2007
- Origin and control of high-temperature ferromagnetism in semiconductorsNature Materials, 2007
- Origin of ferromagnetic response in diluted magnetic semiconductors and oxidesJournal of Physics: Condensed Matter, 2007
- Paramagneticand ferromagnetic: The relationship between structural, electronic, and magnetic propertiesPhysical Review B, 2007
- Theory of ferromagnetic semiconductorsPhysica Status Solidi (a), 2007
- Ferromagnetism in oxide semiconductorsMaterials Today, 2006
- Extended x-ray absorption fine structure—its strengths and limitations as a structural toolReviews of Modern Physics, 1981