The projects in this part of the Interface Physics Group are all performed with the home-built High-Speed, Variable-Temperature Scanning Tunneling Microscope, developed by Kobus Kuipers and Mischa Hoogeman.
Currently, we are developing video-rate STM. 

Using indium atoms, embedded in the outermost atomic layer of the Cu(001) surface, Raoul van Gastel has visualized and quantified the existence and mobility of surface vacancies. An ultralow density of these individual, missing surface atoms, sets the entire surface in motion...

The Au(110) surface exhibits a wealth of peculiar step and island structures, all of them appearing as the result of the Missing-Row Reconstruction of Au(110), in combination with the energetics of this surface. Marcel Rost has investigated the special, 'almond' shapes of islands on this surface, and the uncommon decay dynamics of mounds and pits.

Using mild ion-erosion, small, single-monolayer deep vacancy islands can be produced in Au(110). Marcel Rost has found that, in contrast with the larger, almond-shape islands, these small vacancy islands can have an asymmetric internal structure. To our surprise, the average island shape is completely symmetric! 

With its ordered, half-filled first layer, the Au(110) surface is the perfect candidate for an Ising-type order-disorder transition. In this phase transition, domain boundaries are formed between different regions on the surface, on which the Missing-Row Reconstructions are out of phase with each other. Marcel Rost has used the STM to measure the thermal generation of these domain boundaries.