Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Half-Metallicity And Efficient Spin Injection In Aln/Gan:Cr (0001) Heterostructure, Julia E. Medvedeva, X. Y. Cui, C. Stampfl, N. Newman, Arthur J. Freeman
Half-Metallicity And Efficient Spin Injection In Aln/Gan:Cr (0001) Heterostructure, Julia E. Medvedeva, X. Y. Cui, C. Stampfl, N. Newman, Arthur J. Freeman
Physics Faculty Research & Creative Works
First-principles investigations of the structural, electronic, and magnetic properties of Cr-doped AlN/GaN (0001) heterostructures reveal the possibility of efficient spin injection from a ferromagnetic GaN:Cr electrode through an AlN tunnel barrier. We demonstrate that Cr atoms segregate into the GaN region and that these interfaces retain their half-metallic behavior leading to a complete, i.e., 100%, spin polarization of the conduction electrons. This property makes the wide band-gap nitrides doped with Cr to be excellent candidates for high-efficiency magnetoelectronic devices.
Role Of Embedded Clustering In Dilute Magnetic Semiconductors: Cr Doped Gan, Julia E. Medvedeva, B. Delley, N. Newman, C. Stampfl, X. Y. Cui, Arthur J. Freeman
Role Of Embedded Clustering In Dilute Magnetic Semiconductors: Cr Doped Gan, Julia E. Medvedeva, B. Delley, N. Newman, C. Stampfl, X. Y. Cui, Arthur J. Freeman
Physics Faculty Research & Creative Works
Results of extensive density-functional studies provide direct evidence that Cr atoms in Cr:GaN have a strong tendency to form embedded clusters, occupying Ga sites. Significantly, for larger than 2-Cr-atom clusters, states containing antiferromagnetic coupling with net spin in the range 0.06-1.47 µB/Cr are favored. We propose a picture where various configurations coexist and the statistical distribution and associated magnetism will depend sensitively on the growth details. Such a view may elucidate many puzzling observations related to the structural and magnetic properties of III-N and other dilute semiconductors.