Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 68: Semiconductor substrates: Epitaxy and growth

O 68.4: Vortrag

Donnerstag, 25. März 2010, 11:15–11:30, H42

Structural and electronic properties of MnGa monolayers on wurzite GaN(0001) surface — •Kangkang Wang, Abhijit Chinchore, Meng Shi, and Arthur Smith — Ohio University, Athens, OHIO, U.S.A.

Ferromagnetic (FM) metal/semiconductor bilayers are of great interest due to their importance in novel spintronics applications, such as spin injection and spin light-emitting diodes[1]. It has been reported[2] that delta-MnGa, a FM alloy with curie temperature higher than room temperature (RT), can be grown epitaxial on top of w-GaN(0001) with sharp interface and controllable magnetism. Using molecular beam epitaxy, we deposit up to 3 monolayers (ML's) of Mn onto w-GaN(0001) ''1x1'' surface, which forms Mn(x)Ga(1-x) with x varying from 0 to ~0.6. Mn-induced surface reconstructions and formation of Mn(x)Ga(1-x) crystalline phases are observed by reflection high-energy electron diffraction (RHEED), Auger electron spectroscopy as well as in-situ RT-STM. The data suggests large-period reconstructions upon deposition of <0.25ML Mn and quick formation of delta-MnGa at ~1 ML of Mn. Structural and electronic properties at representative stages will be presented, as well as possible magnetic properties of MnGa ML's. This work has been supported by DOE (Grant No.DE-FG02-06ER46317) and NSF (Grant No.0730257). Equipment support from ONR is also acknowledged.

[1] S.A.Wolf et al, Science 294, 1488 (2001)

[2] E.Lu et al, Phys.Rev.Lett. 97, 146101 (2006) K.K.Wang et al, Mater.Res.Soc.Symp.Proc.1118-K06-06 (2009)