Paper MI-ThA10
Atomic and Electronic Structure of Manganese Alloys on Ge(100) Surface

Thursday, October 18, 2007, 5:00 pm, Room 619

Ferromagnetic metals on semiconducting surfaces are promising for spintronics application. The surface structures of Mn5Ge3(111) alloy on Ge(100) surfaces were studied with scanning tunneling microscope. The plateau structures of Mn5Ge3 were prepared by solid phase epitaxy. Clear hexagonal atomic structures were observed on top of the plateau structures. In support of diffraction experiments and previous theoretical predictions, we were able to confirm that the plateau structures are Mn5Ge3 alloys with the top surfaces along (111) directions. Several atomic patterns, with strong bias-energy dependence, were observed in topography images. As the patterns are compared with theoretical predictions, it is believed that the atomic structures of second layers were observed at certain energy levels. Three types of defect structures were observed in STM images, whose atomic structures will be discussed.