Atomic slide puzzle: Self-diffusion of an impure atom

1 Diffusion on and in Surfaces : the Atomic Slide Puzzle

This paper presents first results from scanning tunneling microscopy measurements, which show that a close-packed terrace of a metal surface can be far from static, even at temperatures as low as room temperature. We make the motion visible of the atoms in a Cu(001) terrace, by embedding a low density of In atoms in the first Cu layer. The peculiar characteristics of the motion of the In show t...

Atomic Self-diffusion in Quasicrystals

A molecular dynamics study on atomic self-diffusion in Frank-Kasper type dodecagonal quasicrystals is presented. It is found that the quasicrystal-specific flip mechanism for atomic diffusion, predicted by Kalugin and Katz, indeed occurs in this system. However, in order to be effective, this mechanism needs to be catalyzed by other defects, such as half-vacancies. For this reason, flip diffusi...

More pieces of the platelet activation puzzle slide into place.

An Tmplementation of Impure Suprogates

Surrogates or internal identifiers can be made to facilitate both fast access and storage independence if they are implemented properly. Such an implementation is discussed here; it permits the tuplcs of a relation to be accessed very fast by primary key for both random and sequential search without retarding the performance of secondary keys. It employs a key compression and a hasiiing algorit...

The Puzzle of Policy Diffusion