5,374 research outputs found
Contrasting Behavior of Carbon Nucleation in the Initial Stages of Graphene Epitaxial Growth on Stepped Metal Surfaces
Using first-principles calculations within density functional theory, we
study the energetics and kinetics of carbon nucleation in the early stages of
epitaxial graphene growth on three representative stepped metal surfaces:
Ir(111), Ru(0001), and Cu(111). We find that on the flat surfaces of Ir(111)
and Ru(0001), two carbon atoms repel each other, while they prefer to form a
dimer on Cu(111). Moreover, the step edges on Ir and Ru surfaces cannot serve
as effective trapping centers for single carbon adatoms, but can readily
facilitate the formation of carbon dimers. These contrasting behaviors are
attributed to the delicate competition between C-C bonding and C-metal bonding,
and a simple generic principle is proposed to predict the nucleation sites of C
adatoms on many other metal substrates with the C-metal bond strengths as the
minimal inputs.Comment: 4 figures, submitted versio
Principal-Agent Conflict and Seller\u27s Strategy Approaching Listing Contract Expiration
Real estate markets are excellent venues in which to study principal-agent incentive misalignments. Buyers and sellers who face relatively higher information costs rely on agents to reduce information costs and to assist their negotiation. Previous literature has focused on a typical dilemma real estate gents face - sales price versus time on market (TOM). This paper analyzes sellers\u27 behavior when an exclusive listing contract nears unsuccessful expiration
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