Element resolved magnetic moments in Mn-doped GaAs

X-ray absorption spectroscopy (XAS) and XMCD measurements reveal induced host magnetic moments in Mn-doped GaAs ferromagnets. These materials are of great interest for devices utilizing the electron spin as well as its charge (spintronics). Theories predict that Mn ions induce polarized valence band states which mediate the magnetic coupling, resulting in small magnetic moments on the semiconductor host elements. XMCD at the Mn, Ga, and As L edges in a 7% Mn-doped GaAs show induced moments at the Ga and As sites with 4s orbital character. Selection rules indicate that the As moment is larger than the Ga moment, and that all moments align as predicted by the valence-band hole coupling mechanism. [Phys. Rev. Lett. 91, 187203 (2003)].

Local Contact: Dave Keavney ( keavney@aps.anl.gov)

Posted by: Becky Gagnon ( gagnon@aps.anl.gov)
Content by: Jonathan Lang ( lang@aps.anl.gov)