Determining the energetics of vicinal perovskite oxide surfaces

The energetics of vicinal SrTiO$_3$(001) and DyScO$_3$(110), prototypical perovskite vicinal surfaces, has been studied using topographic atomic force microscopy imaging. The kink formation and strain relaxation energies are extracted from a statistical analysis of the step meandering. Both perovskite surfaces have very similar kink formation energies and exhibit a similar triangular step undulation. Our experiments suggest that the energetics of perovskite oxide surfaces is mainly governed by the local oxygen coordination.Comment: 16 pages, 4 figure

Effect of moir\'e superlattice reconstruction in the electronic excitation spectrum of graphene-metal heterostructures

We have studied the electronic excitation spectrum in periodically rippled graphene on Ru(0001) and flat, commensurate graphene on Ni(111) by means of high-resolution electron energy loss spectroscopy and a combination of density functional theory and tight-binding approaches. We show that the periodic moir\'e superlattice originated by the lattice mismatch in graphene/Ru(0001) induces the emergence of an extra mode, which is not present in graphene/Ni(111). Contrary to the ordinary intra-band plasmon of doped graphene, the extra mode is robust in charge-neutral graphene/metal contacts, having its origin in electron-hole inter-band transitions between van Hove singularities that emerge in the reconstructed band structure, due to the moir\'e pattern superlattice.Comment: Supplemental materials available at http://www.theorphys.science.ru.nl/people/yuan

Tien jaar Monumentenwet 1988

[No abstract available

Boekbespreking

Book reviews of Bert Buizer, Piet Veel en Hans van Weenen (eds.), Atlas van het Oer-IJ-gebied  Jan Boomgaard, Clé Lesger en Kees Zandvliet (eds.), Honderdnegende Jaarboek van het Genootschap Amstelodamum. Oeroud Amsterdam. Een zoektocht naar de vroegste geschiedenis van de stad Ranjith M. Jayasena, Graaf- en modderwerk. Een archeologische stadsgeschiedenis van AmsterdamBoekbesprekingen van  Bert Buizer, Piet Veel en Hans van Weenen (red.), Atlas van het Oer-IJ-gebied  Jan Boomgaard, Clé Lesger en Kees Zandvliet (red.), Honderdnegende Jaarboek van het Genootschap Amstelodamum. Oeroud Amsterdam. Een zoektocht naar de vroegste geschiedenis van de stad Ranjith M. Jayasena, Graaf- en modderwerk. Een archeologische stadsgeschiedenis van Amsterda

Dijken van Nederland

Review of a book authored by Eric-Jan Pleijster and Cees van der Veeken.Review of a book authored by Eric-Jan Pleijster and Cees van der Veeken

On a Ramsey-type problem of Erd\H{o}s and Pach

In this paper we show that there exists a constant $C>0$ such that for any graph $G$ on $Ck\ln k$ vertices either $G$ or its complement $\bar{G}$ has an induced subgraph on $k$ vertices with minimum degree at least $\frac12(k-1)$. This affirmatively answers a question of Erd\H{o}s and Pach from 1983.Comment: 9 pages; in 2nd version, Eoin Long has been added as co-author and the main result is improved by a log k facto