Ames Laboratory
Two part Pb on Si island
Ames Laboratory physicist Michael Tringides has discovered a phenomenon in self-assembling nanomaterials. A single lead-on-silicon island (orange) grown over a substrate step. The island includes both 5-layer (stable) and 4-layer (unstable) heights and shows different nucleation as a function of layer height. An additional small amount of lead was added to test how new islands nucleate on top (the white “blobs”). The 4-layer height has many small islands while the 5-layer height has only a few large, fractal islands. Although the island is a single island with two connected parts, the two parts behave as if they are separate and each has different “reactivity.”
Two part Pb on Si island
Ames Laboratory physicist Michael Tringides has discovered a phenomenon in self-assembling nanomaterials. A single lead-on-silicon island (orange) grown over a substrate step. The island includes both 5-layer (stable) and 4-layer (unstable) heights and shows different nucleation as a function of layer height. An additional small amount of lead was added to test how new islands nucleate on top (the white “blobs”). The 4-layer height has many small islands while the 5-layer height has only a few large, fractal islands. Although the island is a single island with two connected parts, the two parts behave as if they are separate and each has different “reactivity.”