The role of Cr substitution on the ferromagnetic properties of Ga1-xCrxN
| Autor: | Stephen Y. Wu, Lin Gu, Hanxiao Liu, Nathan Newman, Rakesh Singh, David R. Smith |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Physics and Astronomy (miscellaneous) Ferromagnetic material properties Magnetism Annealing (metallurgy) Analytical chemistry Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Magnetic semiconductor Epitaxy equipment and supplies Condensed Matter::Materials Science Ferromagnetism Condensed Matter::Superconductivity Spectroscopy |
| Popis: | Angular-dependent channeling Rutherford Backscattering Spectroscopy (c-RBS) has been used to quantify the fraction of Cr atoms on substitutional, interstitial, and random sites in epitaxial Ga1-xCrxN films grown by reactive molecular-beam epitaxy. The morphology of these films and correlation with their magnetic properties has been investigated. Films grown at temperatures below ~ 750oC have up to 90% of Cr occupying substitutional sites. Post-growth annealing at 825oC results in a systematic drop in the fraction of substitutional Cr as well as a fall off in the ferromagnetic signal. The roles of non-substitutional Cr in transferring charge from the Cr t2 band and segregation of substitutional Cr in the loss of magnetism are discussed. Overall, these results provide strong microscopic evidence that Cr-doped III-N systems are dilute magnetic semiconductors. 10 pages, 4 figures, submitted to APL |
| Databáze: | OpenAIRE |
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