Seminar: Marko Kralj, 12 October 2016

You are cordially invited to the seminar, which will be held on Њendesday, 12 October 2016 at 13:00 in the library reading room “Dr. Dragan Popović" of the Institute of Physics Belgrade.


The talk entitled

Controlling the binding interaction and doping of epitaxial graphene at nano- and micro-scales

Marko Kralj (Institute of Physics, Zagreb)


Abstract of the talk:


The ability to control the growth and/or modifications of novel two-dimensional (2D) materials in situ at the micro- and nano-scale, opens flexibility in design of 2D materials applications.

We use epitaxial graphene on Ir(111) [1] as a model system to explore deposition of atoms and molecules leading to intercalation where species are pushed between graphene and its support. Generally, properties of many layered 2D materials can be manipulated by intercalation. Besides the charge transfer, the intercalation can affect the binding interaction and further properties of graphene, e.g. chemical reactivity [2] or magnetism. We resolve the microscopic mechanism and dynamics of intercalation process in great detail by studying intercalation and entrapment of alkali atoms under epitaxial graphene on Ir(111) in real and reciprocal space by means of LEEM (in situ), STM, ARPES, LEED and vdW-DFT, and find that the intercalation is adjusted by the van der Waals interaction, with the dynamics governed by defects anchored to graphene wrinkles [3].

In a connected study, by using vicinal Ir substrate, we find that the vdW interaction and increased density of anchoring step lines governs a pronounced mesoscopic faceting of stepped substrates upon graphene growth by setting a balance in a competition between an uniaxial strain and graphene binding, the mechanism which should be of relevance for other 2D vdW epitaxial systems and their strain engineering [4].

[1] I. Pletikosić et al., Phys. Rev. Lett. 102, 056808 (2009).

[2] S. Schumacher et al., Nano Lett. 12, 5013-5019 (2013).

[3] M. Petrović et al., Nat. Commun. 4, 2772 (2013).

[4] I. Šrut Rakić et al., Carbon 110, 267-277 (2016).