Visualization of the inverse layer-plus-island growth in Fe islands on W(110) substrate

• We have grown Fe islands on W(110) substrate using the shadow mask technique.
• We have visualized the initial growth stage of the Stranski–Krastanov mode.
• We have controlled the growth mode from island-plus-layer growth to layer-plus-island growth.

Many experiments have been conducted so far to control the growth mode in heterostructures, but success has only been restricted to strain-controlled growth systems. In this study, using the shadow mask deposition technique, we have changed the growth mode in the Fe/W heterostructures from the layer-plus-island growth mode to island-plus-layer growth mode. From this, we have ignited the competing growth between forming the islands and wetting the first layer, and have directly visualized the island-plus-layer growth by controlling the annealing temperature of the system. This unconventional growth mode may play an important role in studying the hidden boundaries of hetero-interfaces.