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O: Fachverband Oberflächenphysik

O 41: Nanostructures at Surfaces: Metals, Oxides and Semiconductors II

O 41.3: Vortrag

Dienstag, 21. März 2017, 14:30–14:45, REC/PHY C213

A monolayer of hexagonal boron nitride on Ir(111) as a template for cluster growth — •Moritz Will¹, Philipp Valerius¹, Charlotte Herbig¹, Vasile Caciuc², Nicolae Atodiresei², and Thomas Michely¹ — ¹II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany — ²Peter Grünberg Institut (PGI) and Institute for Advanced Simulation (IAS), Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Chemical vapor deposition of B₃N₃H₆ molecules on Ir(111) results in a well aligned monolayer of hexagonal boron nitride (h-BN). The center of each unit cell provides a chemisorbed valley area, where h-BN is hybridized with the Ir substrate. Through a scanning tunneling microscopy study we provide evidence that the valley regions are reactive and pin deposited atoms. In consequence, highly regular cluster arrays with a periodicity of 2.9 nm can be formed. For the case of Ir clusters, the size distribution is narrow. The average size can be tuned between a few to about 200 atoms for room temperature deposition. The thermal stability of the clusters is extraordinary, with a decay of the cluster lattice setting only at around 850 K, primarily through intercalation of the cluster material. Regularly positioned C clusters on h-BN are even observed after annealing to 1500 K. Compared to cluster arrays using graphene on Ir(111) as a template, the better order and the higher thermal stability make the arrays on h-BN/Ir(111) superior in terms of potential applications for nano-catalysis. We elucidated the cluster binding mechanism of Ir clusters to h-BN/Ir(111) with the help of density functional theory calculations.