Intercalated rare-earth metals under graphene on SiC

Anderson, Nathaniel; Hupalo, Myron; Keavney, David; Tringides, Michael; Vaknin, David

Intercalated rare-earth metals under graphene on SiC

File

IS_J_9884.pdf (1.43 MB)

Date

2018-11-03

Authors

Anderson, Nathaniel

Hupalo, Myron

Keavney, David

Tringides, Michael

Vaknin, David

Organizational Units

Organizational Unit

Ames National Laboratory

Ames National Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, Iowa.

For more than 70 years, the Ames National Laboratory has successfully partnered with Iowa State University, and is unique among the 17 DOE laboratories in that it is physically located on the campus of a major research university. Many of the scientists and administrators at the Laboratory also hold faculty positions at the University and the Laboratory has access to both undergraduate and graduate student talent.

Organizational Unit

Physics and Astronomy

Physics and astronomy are basic natural sciences which attempt to describe and provide an understanding of both our world and our universe. Physics serves as the underpinning of many different disciplines including the other natural sciences and technological areas.

Department

Ames National LaboratoryPhysics and Astronomy

Abstract

Intercalation of rare earth metals (RE = Eu, Dy, and Gd) is achieved by depositing the RE metal on graphene that is grown on silicon-carbide (SiC) and by subsequent annealing at high temperatures to promote intercalation. STM images of the films reveal that the graphene layer is defect free and that each of the intercalated metals has a distinct nucleation pattern. Intercalated Eu forms nano-clusters that are situated on the vertices of a Moirè pattern, while Dy and Gd form randomly distributed nano-clusters. X-ray magnetic circular dichroism (XMCD) measurements of intercalated films reveal the magnetic properties of these REs nano-clusters. Furthermore, field dependence and temperature dependence of the magnetic moments extracted from the XMCD show paramagnetic-like behaviors with moments that are generally smaller than those predicted by the Brillouin function. XMCD measurements of RE-oxides compared with those of the intercalated REs under graphene after exposure to air for months indicate that the graphene membranes protect these intercalants against oxidation.